The instant application contains a Sequence Listing which has been submitted electronically in XML format and is hereby incorporated by reference in its entirety. Said XML copy, created on May 16, 2024, is named V2065-700040_SL.xml and is 3,505,256 bytes in size.
Integration of a nucleic acid of interest into a genome occurs at low frequency and with little site specificity, in the absence of a specialized protein to promote the insertion event. Some existing approaches, like CRISPR/Cas9, are more suited for small edits and are less effective at integrating longer sequences. Other existing approaches, like Cre/loxP, require a first step of inserting a loxP site into the genome and then a second step of inserting a sequence of interest into the loxP site. There is a need in the art for improved proteins for inserting sequences of interest into a genome.
This disclosure relates to novel compositions, systems and methods for altering a genome at one or more locations in a host cell, tissue or subject, in vivo or in vitro. In particular, the invention features compositions, systems and methods for the introduction of exogenous genetic elements into a host genome.
Features of the compositions or methods can include one or more of the following enumerated embodiments.
1. A system for modifying DNA comprising:
Domain: The term “domain” as used herein refers to a structure of a biomolecule that contributes to a specified function of the biomolecule. A domain may comprise a contiguous region (e.g., a contiguous sequence) or distinct, non-contiguous regions (e.g., non-contiguous sequences) of a biomolecule. Examples of protein domains include, but are not limited to, an endonuclease domain, a DNA binding domain, a reverse transcription domain; an example of a domain of a nucleic acid is a regulatory domain, such as a transcription factor binding domain.
Exogenous: As used herein, the term exogenous, when used with reference to a biomolecule (such as a nucleic acid sequence or polypeptide) means that the biomolecule was introduced into a host genome, cell or organism by the hand of man. For example, a nucleic acid that is as added into an existing genome, cell, tissue or subject using recombinant DNA techniques or other methods is exogenous to the existing nucleic acid sequence, cell, tissue or subject.
Genomic safe harbor site (GSH site): A genomic safe harbor site is a site in a host genome that is able to accommodate the integration of new genetic material, e.g., such that the inserted genetic element does not cause significant alterations of the host genome posing a risk to the host cell or organism. A GSH site generally meets 1, 2, 3, 4, 5, 6, 7, 8 or 9 of the following criteria: (i) is located >300 kb from a cancer-related gene; (ii) is >300 kb from a miRNA/other functional small RNA; (iii) is >50 kb from a 5′ gene end; (iv) is >50 kb from a replication origin; (v) is >50 kb away from any ultraconservered element; (vi) has low transcriptional activity (i.e. no mRNA+/−25 kb); (vii) is not in copy number variable region; (viii) is in open chromatin; and/or (ix) is unique, with 1 copy in the human genome. Examples of GSH sites in the human genome that meet some or all of these criteria include (i) the adeno-associated virus site 1 (AAVS1), a naturally occurring site of integration of AAV virus on chromosome 19; (ii) the chemokine (C—C motif) receptor 5 (CCR5) gene, a chemokine receptor gene known as an HIV-1 coreceptor; (iii) the human ortholog of the mouse Rosa26 locus; (iv) the rDNA locus. Additional GSH sites are known and described, e.g., in Pellenz et al. epub Aug. 20, 2018 (doi.org/10.1101/396390).
Heterologous: The term heterologous, when used to describe a first element in reference to a second element means that the first element and second element do not exist in nature disposed as described. For example, a heterologous polypeptide, nucleic acid molecule, construct or sequence refers to (a) a polypeptide, nucleic acid molecule or portion of a polypeptide or nucleic acid molecule sequence that is not native to a cell in which it is expressed, (b) a polypeptide or nucleic acid molecule or portion of a polypeptide or nucleic acid molecule that has been altered or mutated relative to its native state, or (c) a polypeptide or nucleic acid molecule with an altered expression as compared to the native expression levels under similar conditions. For example, a heterologous regulatory sequence (e.g., promoter, enhancer) may be used to regulate expression of a gene or a nucleic acid molecule in a way that is different than the gene or a nucleic acid molecule is normally expressed in nature. In another example, a heterologous domain of a polypeptide or nucleic acid sequence (e.g., a DNA binding domain of a polypeptide or nucleic acid encoding a DNA binding domain of a polypeptide) may be disposed relative to other domains or may be a different sequence or from a different source, relative to other domains or portions of a polypeptide or its encoding nucleic acid. In certain embodiments, a heterologous nucleic acid molecule may exist in a native host cell genome, but may have an altered expression level or have a different sequence or both. In other embodiments, heterologous nucleic acid molecules may not be endogenous to a host cell or host genome but instead may have been introduced into a host cell by transformation (e.g., transfection, electroporation), wherein the added molecule may integrate into the host genome or can exist as extra-chromosomal genetic material either transiently (e.g., mRNA) or semi-stably for more than one generation (e.g., episomal viral vector, plasmid or other self-replicating vector).
Mutation or Mutated: The term “mutated” when applied to nucleic acid sequences means that nucleotides in a nucleic acid sequence may be inserted, deleted or changed compared to a reference (e.g., native) nucleic acid sequence. A single alteration may be made at a locus (a point mutation) or multiple nucleotides may be inserted, deleted or changed at a single locus. In addition, one or more alterations may be made at any number of loci within a nucleic acid sequence. A nucleic acid sequence may be mutated by any method known in the art.
Nucleic acid molecule: Nucleic acid molecule refers to both RNA and DNA molecules including, without limitation, cDNA, genomic DNA and mRNA, and also includes synthetic nucleic acid molecules, such as those that are chemically synthesized or recombinantly produced, such as RNA templates, as described herein. The nucleic acid molecule can be double-stranded or single-stranded, circular or linear. If single-stranded, the nucleic acid molecule can be the sense strand or the antisense strand. Unless otherwise indicated, and as an example for all sequences described herein under the general format “SEQ. ID NO:,” “nucleic acid comprising SEQ. ID NO:1” refers to a nucleic acid, at least a portion which has either (i) the sequence of SEQ. ID NO: 1, or (ii) a sequence complimentary to SEQ. ID NO:1. The choice between the two is dictated by the context in which SEQ. ID NO:1 is used. For instance, if the nucleic acid is used as a probe, the choice between the two is dictated by the requirement that the probe be complimentary to the desired target. Nucleic acid sequences of the present disclosure may be modified chemically or biochemically or may contain non-natural or derivatized nucleotide bases, as will be readily appreciated by those of skill in the art. Such modifications include, for example, labels, methylation, substitution of one or more naturally occurring nucleotides with an analog, inter-nucleotide modifications such as uncharged linkages (for example, methyl phosphonates, phosphotriesters, phosphoramidates, carbamates, etc.), charged linkages (for example, phosphorothioates, phosphorodithioates, etc.), pendant moieties, (for example, polypeptides), intercalators (for example, acridine, psoralen, etc.), chelators, alkylators, and modified linkages (for example, alpha anomeric nucleic acids, etc.). Also included are synthetic molecules that mimic polynucleotides in their ability to bind to a designated sequence via hydrogen bonding and other chemical interactions. Such molecules are known in the art and include, for example, those in which peptide linkages substitute for phosphate linkages in the backbone of a molecule. Other modifications can include, for example, analogs in which the ribose ring contains a bridging moiety or other structure such as modifications found in “locked” nucleic acids.
Gene expression unit: a gene expression unit is a nucleic acid sequence comprising at least one regulatory nucleic acid sequence operably linked to at least one effector sequence. A first nucleic acid sequence is operably linked with a second nucleic acid sequence when the first nucleic acid sequence is placed in a functional relationship with the second nucleic acid sequence. For instance, a promoter or enhancer is operably linked to a coding sequence if the promoter or enhancer affects the transcription or expression of the coding sequence. Operably linked DNA sequences may be contiguous or non-contiguous. Where necessary to join two protein-coding regions, operably linked sequences may be in the same reading frame.
Host: The terms host genome or host cell, as used herein, refer to a cell and/or its genome into which protein and/or genetic material has been introduced. It should be understood that such terms are intended to refer not only to the particular subject cell and/or genome, but to the progeny of such a cell and/or the genome of the progeny of such a cell. Because certain modifications may occur in succeeding generations due to either mutation or environmental influences, such progeny may not, in fact, be identical to the parent cell, but are still included within the scope of the term “host cell” as used herein. A host genome or host cell may be an isolated cell or cell line grown in culture, or genomic material isolated from such a cell or cell line, or may be a host cell or host genome which composing living tissue or an organism. In some instances, a host cell may be an animal cell or a plant cell, e.g., as described herein. In certain instances, a host cell may be a bovine cell, horse cell, pig cell, goat cell, sheep cell, chicken cell, or turkey cell. In certain instances, a host cell may be a corn cell, soy cell, wheat cell, or rice cell.
Pseudoknot: A “pseudoknot sequence” sequence, as used herein, refers to a nucleic acid (e.g., RNA) having a sequence with suitable self-complementarity to form a pseudoknot structure, e.g., having: a first segment, a second segment between the first segment and a third segment, wherein the third segment is complementary to the first segment, and a fourth segment, wherein the fourth segment is complementary to the second segment. The pseudoknot may optionally have additional secondary structure, e.g., a stem loop disposed in the second segment, a stem-loop disposed between the second segment and third segment, sequence before the first segment, or sequence after the fourth segment. The pseudoknot may have additional sequence between the first and second segments, between the second and third segments, or between the third and fourth segments. In some embodiments, the segments are arranged, from 5′ to 3′: first, second, third, and fourth. In some embodiments, the first and third segments comprise five base pairs of perfect complementarity. In some embodiments, the second and fourth segments comprise 10 base pairs, optionally with one or more (e.g., two) bulges. In some embodiments, the second segment comprises one or more unpaired nucleotides, e.g., forming a loop. In some embodiments, the third segment comprises one or more unpaired nucleotides, e.g., forming a loop.
Stem-loop sequence: As used herein, a “stem-loop sequence” refers to a nucleic acid sequence (e.g., RNA sequence) with sufficient self-complementarity to form a stem-loop, e.g., having a stem comprising at least two (e.g., 3, 4, 5, 6, 7, 8, 9, or 10) base pairs, and a loop with at least three (e.g., four) base pairs. The stem may comprise mismatches or bulges.
This disclosure relates to compositions, systems and methods for targeting, editing, modifying or manipulating a DNA sequence (e.g., inserting a heterologous object DNA sequence into a target site of a mammalian genome) at one or more locations in a DNA sequence in a cell, tissue or subject, e.g., in vivo or in vitro. The object DNA sequence may include, e.g., a coding sequence, a regulatory sequence, a gene expression unit.
More specifically, the disclosure provides retrotransposon-based systems for inserting a sequence of interest into the genome. This disclosure is based, in part, on a bioinformatic analysis to identify retrotransposase sequences and the associated 5′ UTR and 3′ UTR from a variety of organisms (see Table 3). While not wishing to be bound by theory, in some embodiments, retrotransposases identified in homeothermic (warm blooded) species, like birds, may have improved thermostability relative to some other enzymes that evolved at lower temperatures, and the thermostable retrotransposases may therefore be better suited for use in human cells. The disclosure also provides experimental evidence that several retrotransposases from different species, e.g., different species of animal and/or different species and clade of retrotransposon (e.g., as grouped by reverse transcriptase phylogeny, e.g., as described in Su et al. (2019) RNA; incorporated herein by reference in its entirety), can be used to catalyze DNA insertion into a target site in human cells (see Examples 7 and Example 28).
In some embodiments, systems described herein can have a number of advantages relative to various earlier systems. For instance, the disclosure describes retrotransposases capable of inserting long sequences (e.g., over 3000 nucleotides) of heterologous nucleic acid into a genome (see, e.g.,
Non-long terminal repeat (LTR) retrotransposons are a type of mobile genetic elements that are widespread in eukaryotic genomes. They include two classes: the apurinic/apyrimidinic endonuclease (APE)-type and the restriction enzyme-like endonuclease (RLE)-type. The APE class retrotransposons are comprised of two functional domains: an endonuclease/DNA binding domain, and a reverse transcriptase domain. The RLE class are comprised of three functional domains: a DNA binding domain, a reverse transcription domain, and an endonuclease domain. The reverse transcriptase domain of non-LTR retrotransposon functions by binding an RNA sequence template and reverse transcribing it into the host genome's target DNA. The RNA sequence template has a 3′ untranslated region which is specifically bound to the transposase, and a variable 5′ region generally having Open Reading Frame(s) (“ORF”) encoding transposase proteins. The RNA sequence template may also comprise a 5′ untranslated region which specifically binds the retrotransposase.
The inventors have found that, surprisingly, the elements of such non-LTR retrotransposons can be functionally modularized and/or modified to target, edit, modify or manipulate a target DNA sequence, e.g., to insert an object (e.g., heterologous) nucleic acid sequence into a target genome, e.g., a mammalian genome, by reverse transcription. Such modularized and modified nucleic acids, polypeptide compositions and systems are described herein and are referred to as GENE WRITER™ gene editors. A GENE WRITER™ gene editor system comprises: (A) a polypeptide or a nucleic acid encoding a polypeptide, wherein the polypeptide comprises (i) a reverse transcriptase domain, and either (x) an endonuclease domain that contains DNA binding functionality or (y) an endonuclease domain and separate DNA binding domain; and (B) a template RNA comprising (i) a sequence that binds the polypeptide and (ii) a heterologous insert sequence. For example, the GENE WRITER™ genome editor protein may comprise a DNA-binding domain, a reverse transcriptase domain, and an endonuclease domain. In other embodiments, the GENE WRITER™ genome editor protein may comprise a reverse transcriptase domain and an endonuclease domain. In certain embodiments, the elements of the GENE WRITER™ gene editor polypeptide can be derived from sequences of non-LTR retrotransposons, e.g., APE-type or RLE-type retrotransposons or portions or domains thereof. In some embodiments the RLE-type non-LTR retrotransposon is from the R2, NeSL, HERO, R4, or CRE clade. In some embodiments the GENE WRITER™ genome editor is derived from R4 element X4_Line, which is found in the human genome. In some embodiments the APE-type non-LTR retrotransposon is from the R1, or Tx1 clade. In some embodiments the GENE WRITER™ genome editor is derived from Tx1 element Mare6, which is found in the human genome. The RNA template element of a GENE WRITER™ gene editor system is typically heterologous to the polypeptide element and provides an object sequence to be inserted (reverse transcribed) into the host genome. In some embodiments the GENE WRITER™ genome editor protein is capable of target primed reverse transcription.
In some embodiments the GENE WRITER™ genome editor is combined with a second polypeptide. In some embodiments the second polypeptide is derived from an APE-type non-LTR retrotransposon. In some embodiments the second polypeptide has a zinc knuckle-like motif. In some embodiments the second polypeptide is a homolog of Gag proteins.
In certain aspects of the present invention, the reverse transcriptase domain of the GENE WRITER™ system is based on a reverse transcriptase domain of an APE-type or RLE-type non-LTR retrotransposon. A wild-type reverse transcriptase domain of an APE-type or RLE-type non-LTR retrotransposon can be used in a GENE WRITER™ system or can be modified (e.g., by insertion, deletion, or substitution of one or more residues) to alter the reverse transcriptase activity for target DNA sequences. In some embodiments the reverse transcriptase is altered from its natural sequence to have altered codon usage, e.g. improved for human cells. In some embodiments the reverse transcriptase domain is a heterologous reverse transcriptase from a different retrovirus, LTR-retrotransposon, or non-LTR retrotransposon. In certain embodiments, a GENE WRITER™ system includes a polypeptide that comprises a reverse transcriptase domain of an RLE-type non-LTR retrotransposon from the R2, NeSL, HERO, R4, or CRE clade, or of an APE-type non-LTR retrotransposon from the R1, or Tx1 clade. In certain embodiments, a GENE WRITER™ system includes a polypeptide that comprises a reverse transcriptase domain of a retrotransposon listed in Table 1, Table 2, or Table 3. In embodiments, the amino acid sequence of the reverse transcriptase domain of a GENE WRITER™ system is at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99% identical to the amino acid sequence of a reverse transcriptase domain of a retrotransposon whose DNA sequence is referenced in Table 1, Table 2, or Table 3. A person having ordinary skill in the art is capable of identifying reverse transcription domains based upon homology to other known reverse transcription domains using routine tools as Basic Local Alignment Search Tool (BLAST). In some embodiments, reverse transcriptase domains are modified, for example by site-specific mutation. In embodiments, the reverse transcriptase domain is engineered to bind a heterologous template RNA.
In certain embodiments, the endonuclease/DNA binding domain of an APE-type retrotransposon or the endonuclease domain of an RLE-type retrotransposon can be used or can be modified (e.g., by insertion, deletion, or substitution of one or more residues) in a GENE WRITER™ system described herein. In some embodiments the endonuclease domain or endonuclease/DNA binding domain is altered from its natural sequence to have altered codon usage, e.g. improved for human cells. In some embodiments the endonuclease element is a heterologous endonuclease element, such as Fok1 nuclease, a type-II restriction 1-like endonuclease (RLE-type nuclease), or another RLE-type endonuclease (also known as REL). In some embodiments the heterologous endonuclease activity has nickase activity and does not form double stranded breaks. The amino acid sequence of an endonuclease domain of a GENE WRITER™ system described herein may be at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99% identical to the amino acid sequence of an endonuclease domain of a retrotransposon whose DNA sequence is referenced in Table 1, 2, or 3. A person having ordinary skill in the art is capable of identifying endounclease domains based upon homology to other known endonuclease domains using tools as Basic Local Alignment Search Tool (BLAST). In certain embodiments, the heterologous endonuclease is Fok1 or a functional fragment thereof. In certain embodiments, the heterologous endonuclease is a Holliday junction resolvase or homolog thereof, such as the Holliday junction resolving enzyme from Sulfolobus solfataricus-Ssol Hje (Govindaraju et al., Nucleic Acids Research 44:7, 2016). In certain embodiments, the heterologous endonuclease is the endonuclease of the large fragment of a spliceosomal protein, such as Prp8 (Mahbub et al., Mobile DNA 8:16, 2017). For example, a GENE WRITER™ polypeptide described herein may comprise a reverse transcriptase domain from an APE- or RLE-type retrotransposon and an endonuclease domain that comprises Fok1 or a functional fragment thereof. In still other embodiments, homologous endonuclease domains are modified, for example by site-specific mutation, to alter DNA endonuclease activity. In still other embodiments, endonuclease domains are modified to remove any latent DNA-sequence specificity.
In certain aspects, the DNA-binding domain of a GENE WRITER™ polypeptide described herein is selected, designed, or constructed for binding to a desired host DNA target sequence. In certain embodiments, the DNA-binding domain of the engineered RLE is a heterologous DNA-binding protein or domain relative to a native retrotransposon sequence. In some embodiments the heterologous DNA binding element is a zinc-finger element or a TAL effector element, e.g., a zinc-finger or TAL polypeptide or functional fragment thereof. In some embodiments the heterologous DNA binding element is a sequence-guided DNA binding element, such as Cas9, Cpf1, or other CRISPR-related protein that has been altered to have no endonuclease activity. In some embodiments the heterologous DNA binding element retains endonuclease activity. In some embodiments the heterologous DNA binding element replaces the endonuclease element of the polypeptide. In specific embodiments, the heterologous DNA-binding domain can be any one or more of Cas9, TAL domain, ZF domain, Myb domain, combinations thereof, or multiples thereof. In certain embodiments, the heterologous DNA-binding domain is a DNA binding domain of a retrotransposon described in Table 1, Table 2, or Table 3. A person having ordinary skill in the art is capable of identifying DNA binding domains based upon homology to other known DNA binding domains using tools as Basic Local Alignment Search Tool (BLAST). In still other embodiments, DNA-binding domains are modified, for example by site-specific mutation, increasing or decreasing DNA-binding elements (for example, number and/or specificity of zinc fingers), etc., to alter DNA-binding specificity and affinity. In some embodiments the DNA binding domain is altered from its natural sequence to have altered codon usage, e.g. improved for human cells
In certain aspects of the present invention, the host DNA-binding site integrated into by the GENE WRITER™ system can be in a gene, in an intron, in an exon, an ORF, outside of a coding region of any gene, in a regulatory region of a gene, or outside of a regulatory region of a gene. In other aspects, the engineered RLE may bind to one or more than one host DNA sequence.
In certain embodiments, a GENE WRITER™ gene editor system RNA further comprises an intracellular localization sequence, e.g., a nuclear localization sequence. The nuclear localization sequence may be an RNA sequence that promotes the import of the RNA into the nucleus. In certain embodiments the nuclear localization signal is located on the template RNA. In certain embodiments, the retrotransposase polypeptide is encoded on a first RNA, and the template RNA is a second, separate, RNA, and the nuclear localization signal is located on the template RNA and not on an RNA encoding the retrotransposase polypeptide. While not wishing to be bound by theory, in some embodiments, the RNA encoding the retrotransposase is targeted primarily to the cytoplasm to promote its translation, while the template RNA is targeted primarily to the nucleus to promote its retrotransposition into the genome. In some embodiments the nuclear localization signal is at the 3′ end, 5′ end, or in an internal region of the template RNA. In some embodiments the nuclear localization signal is 3′ of the heterologous sequence (e.g., is directly 3′ of the heterologous sequence) or is 5′ of the heterologous sequence (e.g., is directly 5′ of the heterologous sequence). In some embodiments the nuclear localization signal is placed outside of the 5′ UTR or outside of the 3′ UTR of the template RNA. In some embodiments the nuclear localization signal is placed between the 5′ UTR and the 3′ UTR, wherein optionally the nuclear localization signal is not transcribed with the transgene (e.g., the nuclear localization signal is an anti-sense orientation or is downstream of a transcriptional termination signal or polyadenylation signal). In some embodiments the nuclear localization sequence is situated inside of an intron. In some embodiments a plurality of the same or different nuclear localization signals are in the RNA, e.g., in the template RNA. In some embodiments the nuclear localization signal is less than 5, 10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900 or 1000 bp in legnth. Various RNA nuclear localization sequences can be used. For example, Lubelsky and Ulitsky, Nature 555 (107-111), 2018 describe RNA sequences which drive RNA localization into the nucleus. In some embodiments, the nuclear localization signal is a SINE-derived nuclear RNA localization (SIRLOIN) signal. In some embodiments the nuclear localization signal binds a nuclear-enriched protein. In some embodiments the nuclear localization signal binds the HNRNPK protein. In some embodiments the nuclear localization signal is rich in pyrimidines, e.g., is a C/T rich, C/U rich, C rich, T rich, or U rich region. In some embodiments the nuclear localization signal is derived from a long non-coding RNA. In some embodiments the nuclear localization signal is derived from MALAT1 long non-coding RNA or is the 600 nucleotide M region of MALAT1 (described in Miyagawa et al., RNA 18, (738-751), 2012). In some embodiments the nuclear localization signal is derived from BORG long non-coding RNA or is a AGCCC motif (described in Zhang et al., Molecular and Cellular Biology 34, 2318-2329 (2014). In some embodiments the nuclear localization sequence is described in Shukla et al., The EMBO Journal e98452 (2018). In some embodiments the nuclear localization signal is derived from a non-LTR retrotransposon, an LTR retrotransposon, retrovirus, or an endogenous retrovirus.
In certain embodiments, a GENE WRITER™ gene editor system polypeptide further comprises an intracellular localization sequence, e.g., a nuclear localization sequence and/or a nucleolar localization sequence. The nuclear localization sequence and/or nucleolar localization sequence may be amino acid sequences that promote the import of the protein into the nucleus and/or nucleolus, where it can promote integration of heterologous sequyence into the genome. In certain embodiments, a GENE WRITER™ gene editor system polypeptide (e.g., a retrotransposase, e.g., a polypeptide according to any of Tables 1, 2, or 3 herein) further comprises a nucleolar localization sequence. In certain embodiments, the retrotransposase polypeptide is encoded on a first RNA, and the template RNA is a second, separate, RNA, and the nucleolar localization signal is encoded on the RNA encoding the retrotransposase polypeptide and not on the template RNA. In some embodiments, the nucleolar localization signal is located at the N-terminus, C-terminus, or in an internal region of the polypeptide. In some embodiments, a plurality of the same or different nucleolar localization signals are used. In some embodiments, the nuclear localization signal is less than 5, 10, 25, 50, 75, or 100 amino acids in length. Various polypeptide nucleolar localization signals can be used. For example, Yang et al., Journal of Biomedical Science 22, 33 (2015), describe a nuclear localization signal that also functions as a nucleolar localization signal. In some embodiments, the nucleolar localization signal may also be a nuclear localization signal. In some embodiments, the nucleolar localization signal may overlap with a nuclear localization signal. In some embodiments, the nucleolar localization signal may comprise a stretch of basic residues. In some embodiments, the nucleolar localization signal may be rich in arginine and lysine residues. In some embodiments, the nucleolar localization signal may be derived from a protein that is enriched in the nucleolus. In some embodiments, the nucleolar localization signal may be derived from a protein enriched at ribosomal RNA loci. In some embodiments, the nucleolar localization signal may be derived from a protein that binds rRNA. In some embodiments, the nucleolar localization signal may be derived from MSP58. In some embodiments, the nucleolar localization signal may be a monopartite motif. In some embodiments, the nucleolar localization signal may be a bipartite motif. In some embodiments, the nucleolar localization signal may consist of a multiple monopartite or bipartite motifs. In some embodiments, the nucleolar localization signal may consist of a mix of monopartite and bipartite motifs. In some embodiments, the nucleolar localization signal may be a dual bipartite motif. In some embodiments, the nucleolar localization motif may be a KRASSQALGTIPKRRSSSRFIKRKK (SEQ ID NO: 1530). In some embodiments, the nucleolar localization signal may be derived from nuclear factor-KB-inducing kinase. In some embodiments, the nucleolar localization signal may be an RKKRKKK motif (SEQ ID NO: 1531) (described in Birbach et al., Journal of Cell Science, 117 (3615-3624), 2004).
In some embodiments, a nucleic acid described herein (e.g., an RNA encoding a GENE WRITER™ polypeptide, or a DNA encoding the RNA) comprises a microRNA binding site. In some embodiments, the microRNA binding site is used to increase the target-cell specificity of a GENE WRITER™ system. For instance, the microRNA binding site can be chosen on the basis that is is recognized by a miRNA that is present in a non-target cell type, but that is not present (or is present at a reduced level relative to the non-target cell) in a target cell type. Thus, when the RNA encoding the GENE WRITER™ polypeptide is present in a non-target cell, it would be bound by the miRNA, and when the RNA encoding the GENE WRITER™ polypeptide is present in a target cell, it would not be bound by the miRNA (or bound but at reduced levels relative to the non-target cell). While not wishing to be bound by theory, binding of the miRNA to the RNA encoding the GENE WRITER™ polypeptide may reduce production of the GENE WRITER™ polypeptide, e.g., by degrading the mRNA encoding the polypeptide or by interfering with translation. Accordingly, the heterologous object sequence would be inserted into the genome of target cells more efficiently than into the genome of non-target cells. A system having a microRNA binding site in the RNA encoding the GENE WRITER™ polypeptide (or encoded in the DNA encoding the RNA) may also be used in combination with a template RNA that is regulated by a second microRNA binding site, e.g., as described herein in the section entitled “Template RNA component of GENE WRITER™ gene editor system.”
Danio rerio retrotransposon
Danio rerio
Drosophila melanogaster non-LTR
Drosophila
melanogaster
Tetraodon nigroviridis
Tetraodon
nigroviridis
Danio rerio retrotransposon KenoDr1
Danio rerio
Takifugu rubripes retrotransposon
Takifugu
rubripes
Danio rerio retrotransposon KibiDr2
Danio rerio
Danio rerio retrotransposon KibiDr1
Danio rerio
Tetraodon nigroviridis
Tetraodon
nigroviridis
Takifugu rubripes retrotransposon
Takifugu
rubripes
Tetraodon nigroviridis
Tetraodon
nigroviridis
Danio rerio retrotransposon
Danio rerio
Danio rerio retrotransposon
Danio rerio
Danio rerio retrotransposon
Danio rerio
Trilocha sp. GAS-2011 isolate TrilSp.6
Trilocha
Scopula ornata isolate ScoOrn.6 non-
Scopula ornata
Perigonia ilus isolate PerIlus.31 non-
Perigonia ilus
Oxytenis modestia isolate
Oxytenis
modestia
Oxytenis modestia isolate OxyMod.1
Oxytenis
modestia
Oeneis magna dubia isolate
Oeneis magna
dubia
Lymantria dispar isolate LymDis.2
Lymantria
dispar
Lymantria dispar isolate LymDis.1
Lymantria
dispar
Janiodes laverna isolate JanLav.911
Janiodes
laverna
Janiodes laverna isolate JanLav.811
Janiodes
laverna
Janiodes laverna isolate JanLav.5
Janiodes
laverna
Janiodes laverna isolate JanLav.411
Janiodes
laverna
Janiodes laverna isolate JanLav.211
Janiodes
laverna
Heteropterus morpheus isolate
Heteropterus
morpheus
Erinnyis ello isolate EriEllo.22 non-
Erinnyis ello
Erebia theano isolate EreThe.29 non-
Erebia theano
Erebia theano isolate EreThe.28 non-
Erebia theano
Erebia theano isolate EreThe.27 non-
Erebia theano
Emesis lucinda isolate EmeLuc.23
Emesis lucinda
Emesis lucinda isolate EmeLuc.2 non-
Emesis lucinda
Coenonympha glycerion isolate
Coenonympha
glycerion
Coenonympha glycerion isolate
Coenonympha
glycerion
Coenonympha glycerion isolate
Coenonympha
glycerion
Coenonympha glycerion isolate
Coenonympha
glycerion
Coenonympha glycerion isolate
Coenonympha
glycerion
Coenonympha glycerion isolate
Coenonympha
glycerion
Catocyclotis adelina isolate
Catocyclotis
adelina
Caria rhacotis isolate CarRha.11 non-
Caria rhacotis
Caria rhacotis isolate CarRha.1 non-
Caria rhacotis
Archiearis parthenias isolate BrePar.1
Archiearis
parthenias
Brangas neora isolate BraNeo.32
Brangas neora
Araschnia levana isolate AraLev.31
Araschnia levana
Araschnia levana isolate AraLev.1
Araschnia levana
Anteros formosus isolate AntForm.34
Anteros
formosus
Anteros formosus isolate AntForm.32
Anteros
formosus
Anteros formosus isolate AntForm.31
Anteros
formosus
Agrotis exclamationis isolate
Agrotis
exclamationis
Agrius cingulata isolate
Agrius
cingulata
Agrius cingulata isolate AgrCing.3
Agrius
cingulata
Aglia tau isolate AglTau.8 non-LTR
Aglia tau
Aglia tau isolate AglTau.7 non-LTR
Aglia tau
Maculinea alcon R1-like non-LTR
Phengaris alcon
Maculinea nausithous R1-like non-
Phengaris
nausithous
Bactrocera tryoni clone Btry_5404
Bactrocera
tryoni
Bactrocera tryoni clone Btry_5167
Bactrocera
tryoni
Bactrocera tryoni clone Btry_4956
Bactrocera
tryoni
Bactrocera tryoni clone Btry_5979
Bactrocera
tryoni
Papilio xuthus non-LTR
Papilio xuthus
Papilio xuthus non-LTR
Papilio xuthus
Papilio xuthus non-LTR
Papilio xuthus
Papilio xuthus non-LTR
Papilio xuthus
Papilio xuthus non-LTR
Papilio xuthus
Papilio xuthus non-LTR
Papilio xuthus
Papilio xuthus non-LTR
Papilio xuthus
Papilio xuthus non-LTR
Papilio xuthus
Papilio xuthus non-LTR
Papilio xuthus
Blattella germanica non-LTR
Blattella
germanica
Blattella germanica non-LTR
Blattella
germanica
Dugesiella sp. retrotransposon R1
Aphonopelma
Dugesiella sp. retrotransposon R1
Aphonopelma
Bombyx mori genes for non-LTR
Bombyx mori
Anopheles gambiae retrotransposon
Anopheles
gambiae
Anopheles gambiae retrotransposon
Anopheles
gambiae
Anopheles gambiae retrotransposon
Anopheles
gambiae
Bacillus rossius non-LTR
Bacillus
rossius
Bacillus rossius non-LTR
Bacillus
rossius
Chironomus circumdatus clone cir6
Chironomus
circumdatus
Clelia rustica clone CR6 non-LTR
Paraphimophis
rusticus
Anopheles gambiae retrotransposon
Anopheles
gambiae
Anopheles gambiae retrotransposon
Anopheles
gambiae
Bacillus rossius non-LTR
Bacillus
rossius
Bacillus rossius non-LTR
Bacillus
rossius
Bacillus rossius non-LTR
Bacillus
rossius
Chironomus circumdatus clone cir7
Chironomus
circumdatus
Leptocheirus plumulosus
Leptocheirus
plumulosus
Anopheles gambiae retrotransposon
Anopheles
gambiae
Anopheles gambiae retrotransposon
Anopheles
gambiae
Bombyx mori gene, complete
Bombyx mori
Acyrthosiphon pisum clone LSR1 non-
Acyrthosiphon
pisum
Tetraodon nigroviridis non-LTR
Tetraodon
nigroviridis
Tetraodon nigroviridis partial non-
Tetraodon
nigroviridis
Tetraodon nigroviridis partial non-
Tetraodon
nigroviridis
Tetraodon nigroviridis partial non-
Tetraodon
nigroviridis
Acipenser ruthenus clone dg194
Acipenser
ruthenus
Takifugu rubripes retrotransposon
Takifugu
rubripes
Anopheles gambiae retrotransposon
Anopheles
gambiae
Anopheles gambiae retrotransposon
Anopheles
gambiae
Drosophila melanogaster Waldo-A
Drosophila
melanogaster
Drosophila melanogaster clone CBE9
Drosophila
melanogaster
Drosophila melanogaster Waldo-A
Drosophila
melanogaster
Drosophila melanogaster Waldo-A
Drosophila
melanogaster
Drosophila melanogaster Waldo-B
Drosophila
melanogaster
Drosophila
melanogaster
Drosophila
melanogaster
Anopheles gambiae retrotransposon
Anopheles
gambiae
Anopheles gambiae retrotransposon
Anopheles
gambiae
Forficula scudderi non-LTR
Forficula
scudderi
Forficula scudderi non-LTR
Forficula
scudderi
Forficula scudderi non-LTR
Forficula
scudderi
Colletotrichum cereale
Colletotrichum
cereale
Colletotrichum cereale
Colletotrichum
cereale
Characidium gomesi voucher
Characidium
gomesi
Characidium gomesi non-LTR
Characidim
gomesi
Kalotermes flavicollis
Kalotermes
flavicollis
Crithidia fasciculata
Crithidia
fasciculata
Capsaspora
owczarzaki
Capsaspora
owczarzaki
Capsaspora
owczarzaki
Capsaspora
owczarzaki
Anopheles gambiae
Anopheles
gambiae
Entamoeba histolytica
Entamoeba
histolytica
Entamoeba histolytica
Entamoeba
histolytica
Giardia intestinalis non-LTR
Giardia
intestinalis
Giardia
intestinalis
Giardia
intestinalis
Giardia
intestinalis
Girardia tigrina GENIE
Girardia
tigrina
Giardia
intestinalis
Giardia intestinalis inactive
Giardia
intestinalis
Giardia intestinalis non-LTR
Giardia
intestinalis
Danio rerio retrotransposon
Danio rerio
Takifugu rubripes
Takifugu rubripes
Tetraodon nigroviridis
Tetraodon
nigroviridis
Daphnia pulex non-LTR
Daphnia pulex
Caenorhabditis briggsae
Caenorhabditis
briggsae
Schistosoma
mansoni
Limulus polyphemus
Limulus
polyphemus
Nasonia vitripennis R2 non-LTR
Nasonia
vitripennis
Porcellio scaber
Porcellio scaber
Anurida maritima
Anurida maritima
Bombyx mori rDNA insertion
Bombyx mori
Forficula auricularia
Forficula
auricularia
Triops cancriformis non-LTR
Triops
cancriformis
Reticulitermes lucifugus
Reticulitermes
lucifugus
Ciona intestinalis
Ciona intestinalis
Ciona intestinalis
Ciona intestinalis
Rhynchosciara americana
Rhynchosciara
americana
Ciona intestinalis
Ciona intestinalis
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Rhynchosciara americana
Rhynchosciara
americana
Eyprepocnemis plorans non-LTR
Eyprepocnemis
plorans
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus apus lubbocki
Lepidurus apus
lubbocki
Lepidurus arcticus isolate
Lepidurus arcticus
Lepidurus arcticus isolate
Lepidurus arcticus
Lepidurus arcticus isolate
Lepidurus arcticus
Lepidurus arcticus isolate
Lepidurus arcticus
Lepidurus arcticus isolate
Lepidurus arcticus
Lepidurus arcticus isolate
Lepidurus arcticus
Lepidurus arcticus isolate
Lepidurus arcticus
Lepidurus arcticus isolate
Lepidurus arcticus
Lepidurus arcticus isolate
Lepidurus arcticus
Lepidurus arcticus isolate
Lepidurus arcticus
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Lepidurus couesii isolate
Lepidurus couesii
Tenebrio molitor
Tenebrio molitor
Tenebrio molitor
Tenebrio molitor
Hippodamia convergens
Hippodamia
convergens
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Bacillus rossius isolate
Bacillus rossius
Ciona savignyi
Ciona savignyi
Ciona intestinalis
Ciona intestinalis
Ciona intestinalis
Ciona intestinalis
Ciona intestinalis
Ciona intestinalis
Triops longicaudatus non-LTR
Triops
longicaudatus
Procambarus clarkii non-LTR
Procambarus
clarkii
Hasarius adansoni non-LTR
Hasarius adansoni
Metacrinus rotundus non-LTR
Metacrinus
rotundus
Mauremys reevesii non-LTR
Mauremys reevesii
Mauremys reevesii non-LTR
Mauremys reevesii
Mauremys reevesii non-LTR
Mauremys reevesii
Oryzias latipes non-LTR
Oryzias latipes
Tanichthys albonubes non-LTR
Tanichthys
albonubes
Eptatretus burgeri non-LTR
Eptatretus
burgeri
Aedes aegypti transposon R2-
Aedes aegypti
Aedes aegypti transposon R2-
Aedes aegypti
Kalotermes flavicollis
Kalotermes
flavicollis
Reticulitermes balkanensis
Reticulitermes
balkanensis
Reticulitermes grassei
Reticulitermes
grassei
Reticulitermes urbis non-LTR
Reticulitermes
urbis
Schistosoma japonicum clone
Schistosoma
japonicum
Drosophila mercatorum R2
Drosophila
mercatorum
Bacillus rossius
Bacillus rossius
Limulus polyphemus
Limulus polyphemus
Bombyx mori rDNA insertion
Bombyx mori
Adineta vaga copy 1 non-LTR
Adineta vaga
Bombyx mori non-LTR
Bombyx mori
Ciona intestinalis
Ciona intestinalis
Danio rerio retrotransposon
Danio rerio
Parascaris equorum transposon
Parascaris equorum
Ascaris lumbricoides
Ascaris
lumbricoides
Bombyx mori reverse
Bombyx mori
Maculinea alcon R4-like
Phengaris alcon
Maculinea nausithous R4-like
Phengaris
nausithous
Maculinea nausithous R4-like
Phengaris
nausithous
Maculinea nausithous R4-like
Phengaris
nausithous
Maculinea nausithous R4-like
Phengaris
nausithous
Maculinea nausithous R4-like
Phengaris
nausithous
Maculinea teleius R4-like
Phengaris teleius
Maculinea teleius R4-like
Phengaris teleius
Maculinea teleius R4-like
Phengaris teleius
Maculinea teleius R4-like
Phengaris teleius
Maculinea teleius R4-like
Phengaris teleius
Maculinea teleius R4-like
Phengaris teleius
Maculinea teleius R4-like
Phengaris teleius
Maculinea alcon R4-like
Phengaris alcon
Maculinea nausithous R4-like
Phengaris
nausithous
Maculinea alcon R4-like
Phengaris alcon
Maculinea alcon R4-like
Phengaris alcon
Maculinea alcon R4-like
Phengaris alcon
Maculinea nausithous R4-like
Phengaris
nausithous
Maculinea teleius R4-like
Phengaris teleius
Maculinea alcon R4-like
Phengaris alcon
Maculinea nausithous R4-like
Phengaris
nausithous
Maculinea teleius R4-like
Phengaris teleius
Maculinea teleius R4-like
Phengaris teleius
Xiphophorus maculatus
Xiphophorus
maculatus
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Anopheles merus Amer5 non-LTR
Anopheles merus
Chironomus circumdatus clone
Chironomus
circumdatus
Chironomus alpestris clone
Chironomus
alpestris
Chironomus luridus clone lur5
Chironomus luridus
Beta vulgaris subsp.
Beta vulgaris
vulgaris
Bacillus rossius non-LTR
Bacillus rossius
Bacillus rossius non-LTR
Bacillus rossius
Iberochondrostoma lusitanicum
Iberochondrostoma
lusitanicum
Beta vulgaris subsp.
Beta vulgaris
vulgaris
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Beta vulgaris subsp.
Beta vulgaris
vulgarius
Chironomus circumdatus clone
Chironomus
circumdatus
Beta vulgaris subsp.
Beta vulgaris
vulgaris
Beta vulgaris subsp.
Beta vulgaris
vulgaris
Beta vulgaris subsp.
Beta vulgaris
vulgaris
Beta vulgaris subsp.
Beta vulgaris
vulgaris
Chironomus alpestris clone
Chironomus
alpestris
Beta vulgaris subsp.
Beta vulgaris
vulgaris
Bacillus rossius non-LTR
Bacillus rossius
Oreochromis niloticus Rex6
Oreochromis
niloticus
Oreochromis niloticus Rex6
Oreochromis
niloticus
Oreochromis niloticus Rex6
Oreochromis
niloticus
Xiphophorus maculatus Rex6
Xiphophorus
maculatus
Xiphophorus maculatus Rex6
Xiphophorus
maculatus
Xiphophorus maculatus Rex6
Xiphophorus
maculatus
Xiphophorus maculatus Rex6
Xiphophorus
maculatus
Xiphophorus maculatus Rex6
Xiphophorus
maculatus
Xiphophorus maculatus Rex6
Xiphophorus
maculatus
Poecilia formosa Rex6
Poecilia formosa
Poecilia formosa Rex6
Poecilia formosa
Poecilia formosa Rex6
Poecilia formosa
Poecilia formosa Rex6
Poecilia formosa
Poecilia formosa Rex6
Poecilia formosa
Poecilia formosa Rex6
Poecilia formosa
Poeciliopsis gracilis Rex6
Poeciliopsis
gracilis
Poeciliopsis gracilis Rex6
Poeciliopsis
gracilis
Poeciliopsis gracilis Rex6
Poeciliopsis
gracilis
Poeciliopsis gracilis Rex6
Poeciliopsis
gracilis
Oryzias latipes Rex6
Oryzias latipes
Oryzias latipes Rex6
Oryzias latipes
Oryzias latipes Rex6
Oryzias latipes
Oryzias latipes Rex6
Oryzias latipes
Oryzias latipes Rex6
Oryzias latipes
Cichlasoma labridens Rex6
Herichthys
labridens
Cichlasoma labridens Rex6
Herichthys
labridens
Heterandria bimaculata Rex6
Pseudoxiphophorus
bimaculatus
Heterandria bimaculata Rex6
Pseudoxiphophorus
bimaculatus
Heterandria bimaculata Rex6
Pseudoxiphophorus
bimaculatus
Heterandria bimaculata Rex6
Pseudoxiphophorus
bimaculatus
Heterandria bimaculata Rex6
Pseudoxiphophorus
bimaculatus
Heterandria bimaculata Rex6
Pseudoxiphophorus
bimaculatus
Gambusia affinis Rex6
Gambusia affinis
Gambusia affinis Rex6
Gambusia affinis
Gambusia affinis Rex6
Gambusia affinis
Gambusia affinis Rex6
Gambusia affinis
Gambusia affinis Rex6
Gambusia affinis
Gambusia affinis Rex6
Gambusia affinis
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Symphysodon discus isolate
Symphysodon discus
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Pterophyllum scalare clone
Pterophyllum
scalare
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Geophagus proximus clone
Geophagus proximus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Astronotus ocellatus clone
Astronotus
ocellatus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Cichla monoculus clone
Cichla monoculus
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Silene latifolia isolate
Silene latifolia
Ciona intestinalis
Ciona intestinalis
C. neoformans non-LTR
Cryptococcus
neoformans
Acanthamoeba
castellanii
Bombyx mori
Chondrus crispus
Fragilariopsis
cylindrus
Hydra vulgaris
Helobdella robusta
Lactuca sativa
Monosiga
brevicollis
Nematostella
vectensis
Papilio xuthus
Papilio xuthus: consensus.
Chondrus crispus
Chondrus crispus
Chondrus crispus
Chondrus crispus
Chondrus crispus
Chondrus crispus
Chondrus crispus
Chondrus crispus
Bombyx mori
Chondrus crispus
Hydra vulgaris
Helobdella robusta
Nematostella
vectensis
Papilio xuthus
Papilio xuthus: consensus.
Chondrus crispus
Helobdella robusta
Nematostella
vectensis
Chondrus crispus
Helobdella robusta
Chondrus crispus
Helobdella robusta
Chondrus crispus
Helobdella robusta
Chondrus crispus
Chondrus crispus
Chondrus crispus
C. fasciculata retrotransposable
Crithidia
fasciculata
C. fasciculata retrotransposable
Crithidia
fasciculata
T. cruzi SL-RNA-associated
Trypanosoma cruzi
Bombyx mori non-LTR
Bombyx mori
Takifugu rubripes
Cichlidae
Heliconius
melpomene
melpomene melpomene.
melpomene
Nematostella
vectensis
Nematostella vectensis.
Papilio polytes
Papilio polytes: consensus.
Papilio xuthus
Papilio xuthus: consensus.
Bombyx mori
Heliconius
melpomene
melpomene melpomene.
melpomene
Latimeria
chalumnae
Papilio polytes
Papilio polytes: consensus.
Aedes aegypti
Aedes aegypti.
Anopheles gambiae non-LTR
Anopheles
gambiae
Entamoeba histolytica
Entamoeba
histolytica
Entamoeba histolytica
Entamoeba
histolytica
Cichlidae
Branchiostoma
floridae
Helobdella robusta
Physarum
polycephalm
Strongylocentrotus
purpuratus
Branchiostoma
floridae
Danio rerio
Helobdella robusta
Strongylocentrotus
purpuratus
Branchiostoma
floridae
Danio rerio
Helobdella robusta
Strongylocentrotus
purpuratus
Danio rerio
Helobdella robusta
Helobdella robusta
Helobdella robusta
Helobdella robusta
Helobdella robusta
Helobdella robusta
Danio rerio
Takifugu rubripes
Tetraodon
nigroviridis
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Schmidtea
Schmidtea mediterranea:
mediterranea
Schmidtea
Schmidtea mediterranea:
mediterranea
Schmidtea
Schmidtea mediterranea:
mediterranea
Schmidtea
mediterranea
Schmidtea
mediterranea
Magnaporthe oryzae
Magnaporthe oryzae.
Magnaporthe oryzae
Magnaporthe oryzae.
Caenorhabditis
elegans
Caenorhabditis
tropicalis
Caenorhabditis
angaria
Caenorhabditis
brenneri
Caenorhabditis
briggsae
Caenorhabditis
japonica
Caenorhabditis
remanei
Schmidtea
mediterranea
Trichomonas
vaginalis
Caenorhabditis
brenneri
Caenorhabditis
remanei
Schmidtea
mediterranea
Caenorhabditis
brenneri
Caenorhabditis
remanei
Caenorhabditis
remanei
Schmidtea
mediterranea
Schistosoma mansoni Perere-9
Schistosoma mansoni
Ornithorhynchus
Anurida maritima
Anurida maritima
Bombyx mori rDNA insertion
Bombyx mori
Ciona intestinalis
Chrysemyspicta
bellii
Drosophila
ananassae
Drosophila ananassae.
Drosophila
melanogaster
Drosophila
persimilis
Drosophila persimilis.
Drosophila
pseudoobscura
Drosophila pseudoobscura.
Drosophila
sechellia
Drosophila sechellia.
Drosophila
simulans
Drosophila simulans.
Drosophila yakuba
Drosophila yakuba.
Forficula auricularia
Forficula
auricularia
Hippodamia convergens
Hippodamia
convergens
Kalotermes
flavicollis
Kalotermes flavicollis.
Limulus polyphemus
Limulus polyphemus
Porcellio scaber
Porcellio scaber
Reticulitermes
lucifugus
Reticulitermes lucifugus.
Reticulitermes
urbis
Reticulitermes urbis.
Amblyomma
americanum
Aquila chrysaetos
canadensis
Acanthisitta
chloris
Aptenodytes
forsteri
Alligator
mississippiensis
Apteryx spp.
Apteryx australis
mantelli
Acyrthosiphon
pisum
Balearica
regulorum
gibbericeps
Bombus terrestris
Calypte anna
Cathartes aura
Corvus
brachyrhynchos
Antrostomus
carolinensis
Cuculus canorus
Calidris pugnax
Crocodylus porosus
Colius striatus
Chlamydotis
macqueenii
Charadrius
vociferus
Drosophila
willistoni
Drosophila willistoni.
Egretta garzetta
Ficedula
albicollis
Falco cherrug
Falco peregrinus
Gasterosteus
aculeatus
Gavialis
gangeticus
Geospiza fortis
Gavia stellata
Haliaeetus
albicilla
Ixodes scapularis
Latimeria
chalumnae
Leptosomus
discolor
Lepeophtheirus
salmonis
Lytechinus
variegatus
Mayetiola
destructor
Mnemiopsis leidyi
Megachile
rotundata
Melopsittacus
undulatus
Mesitornis
unicolor
Manacus vitellinus
Nipponia nippon
Nematostella
vectensis
Opisthocomus
hoazin
Pygoscelis adeliae
Pogonomyrmex
barbatus
Phalacrocorax
carbo
Priapulus caudatus
Podiceps cristatus
Pelecanus crispus
Pterocles
gutturalis
Phaethon lepturus
Petromyzon marinus
Phlebotomus
papatasi
Picoides pubescens
Phoenicopterus
ruber ruber
Pelodiscus
sinensis
Rhipicephaus
microplus
Rhodnius prolixus
Rhipicephalus
pulchellus
Serinus canaria
Saccoglossus
kowalevskii
Schmidtea
Schmidtea mediterranea:
mediterranea
Strongylocentrotus
purpuratus
Salmo salar
Struthiocamelus
australis
Tyto alba
Tribolium
castaneum
Taeniopygia
guttata
Tinamus guttatus
Trichinella
spiralis
Trichinella spiralis genome -
Tetranychus
urticae
Xiphophorus
maculatus
Zonotrichia
albicollis
Zosterops
lateralis
melanops
Acyrthosiphon
pisum
Cuculus canorus
Chlamydotis
macqueenii
Drosophila
willistoni
Drosophila willistoni.
Haliaeetus
albicilla
Ixodes scapularis
Megachile
rotundata
Melopsittacus
undulatus
Mesitornis
unicolor
Nipponia nippon
Nematostella
vectensis
Pogonomyrmex
barbatus
Petromyzon marinus
Rhodnius prolixus
Schmidtea
mediterranea
Tribolium
castaneum
Tetranychus
urticae
Ixodes scapularis
Megachile
rotundata
Megachile
rotundata
Megachile
rotundata
Megachile
rotundata
Megachile
rotundata
Megachile
rotundata
Gavialis
gangeticus
Gavialis
gangeticus
Gavialis
gangeticus
Nasonia
vitripennis
Nasonia vitripennis.
Tenebrio molitor
Tenebrio molitor
Apis mellifera
Drosophila mercatorum R2
Drosophila
mercatorum
Nasonia
vitripennis
Nasonia vitripennis.
Tenebrio molitor
Tenebrio molitor
Nasonia giraulti
Nasonia giraulti.
Ciona intestinalis
Ciona intestinalis
Ciona intestinalis
Ciona intestinalis
Ciona intestinalis
Ciona intestinalis
Ciona intestinalis
Ciona savignyi
Nasonia giraulti
Nasonia giraulti.
Danio rerio
Nasonia
longicornis
Nasonia longicornisi.
Eptatretus burgeri
Hasarius adansoni
Lepidurus arcticus
Lepidurus couesii
Lepidurus couesii
Lepidurus couesii
Lepidurus apus
lubbocki
Metacrinus
rotundus
Crassostrea gigas
Crassostrea gigas.
Clonorchis
Clonorchis sinensis: consensus.
sinensis
Patiria miniata
Schmidtea
Schmidtea mediterranea:
mediterranea
Nematostella
vectensis
Nematostella vectensis.
Oryzias latipes
Oryzias latipes - consensus.
Procambarus
clarkii
Schistosoma
mansoni
mansoni.
Tanichthys
albonubes
Triops
cancriformis
Triops
cancriformis
Triops
longicaudatus
Ascaris lumbricoides
Ascaris
lumbricoides
Haemonchus contortus non-LTR
Haemonchus
contortus
Heliconius
melpomene.
melpomene
Anolis
carolinensis
Acropora
digitifera
Bombyx mori
Bursaphelenchus
xylophilus
xylophilus.
Caenorhabditis
japonica
japonica.
Callorhinchus
milii
Chrysemyspicta
bellii
Entamoeba dispar
Heterodera
glycines
Heterodera glycines.
Heliconius
Heliconius melpomene melpomene.
melpomene
melpomene
Meloidogyne
incognita
incognita.
Parhyale
hawaiensis
Strongyloides
ratti
Tribolium
castaneum
Anolis
carolinensis
Ascaris suum
Bursaphelenchus
xylophilus
xylophilus.
Heterodera
glycines
glycines.
Strongyloides
ratti
Bursaphelenchus
xylophilus
xylophilus.
Strongyloides
ratti
Bursaphelenchus
xylophilus
xylophilus.
Strongyloides
ratti
ratti.
Bursaphelenchus
xylophilus
xylophilus.
Girardia tigrina R5
Girardia tigrina
Schmidtea
mediterranea
Schmidtea
mediterranea
Hydra vulgaris
Hydra magnipapillata.
Hydra vulgaris
Hydra magnipapillata.
Adineta vaga
Rhynchosciara
americana
Rhynchosciara americana.
Takifugu rubripes
Oryzias latipes
Trypanosoma brucei DNA for
Trypanosoma brucei
Acanthamoeba
castellanii
Anolis
carolinensis
Acromyrmex
echinatior
Alligator
mississippiensis
Acyrthosiphon
pisum
Agrilus
planipennis
Camponotus
floridanus
Chelonia mydas
Chrysemyspicta
bellii
Crocodylus porosus
Dendroctonus ponderosae
Daphnia pulex
Drosophila yakuba
Eimeria brunetti
Eimeria mitis
Eimeria necatrix
Gavialis
gangeticus
Ganaspis
Hyaloperonospora
arabidopsidis
Heterodera
glycines
Heliconius
melpomene
melpomene
Harpegnathos
saltator
Ixodes scapularis
Lasioglossum
albipes
Ladona fulva
Lytechinus
variegatus
Megachile
rotundata
Nasonia
vitripennis
Phytophthora alni
Pythium
arrhenomanes
Pogonomyrmex
barbatus
Phytophthora
capsici
Phytophthora
cinnamomi
Pseudoperonospora
cubensis
Phytophthora
infestans
Pythium insidiosum
Phytophthora
kernoviae
Phytophthora
lateralis
Patiria miniata
Pristionchus
pacificus
Phytophthora
pinifolia
Phytophthora pinifolia.
Phytophthora
ramorum
Panagrellus
redivivus
Phytophthora sojae
Pelodiscus
sinensis
Parasteatoda
tepidariorum
Pythium ultimum
Phytopythium
Saprolegnia
parasitica
Saprolegnia
diclina
Strigamia maritima
Strongylocentrotus
purpuratus
Trichinella
spiralis
Chrysemys picta
bellii
Acyrthosiphon
pisum
Chelonia mydas
Chrysemys picta
bellii
Daphnia pulex
Ladona fulva
Phytophthora
capsici
Phytophthora
infestans
Phytophthora
ramorum
Phytophthora sojae
Pythium ultimum
Chrysemys picta
bellii
Daphnia pulex
Ladona fulva
Phytophthora
capsici
Phytophthora
infestans
Phytophthora
ramorum
Ladona fulva
Phytophthora
infestans
Phytophthora
ramorum
Ladona fulva
Phytophthora
infestans
Phytophthora
ramorum
Ladona fulva
Vertebrata
Ciona savignyi
Ciona savignyi
Ciona intestinalis
Ciona intestinalis
A skilled artisan can, based on the Accession numbers provided in Tables 1-3 determine the nucleic acid and corresponding polypeptide sequences of each retrotransposon and domains thereof, e.g., by using routine sequence analysis tools as Basic Local Alignment Search Tool (BLAST) or CD-Search for conserved domain analysis. Other sequence analysis tools are known and can be found, e.g., at molbiol-tools.ca, for example, at molbiol-tools.ca/Motifs.htm. SEQ ID NOs 1-112 align with each row in Table 1, and SEQ ID NOs 113-1015 align with the first 903 rows of Table 2.
Tables 1-3 herein provide the sequences of exemplary transposons, including the amino acid sequence of the retrotransposase, and sequences of 5′ and 3′ untranslated regions to allow the retrotransposase to bind the template RNA, and the full transposon nucleic acid sequence. In some embodiments, a 5′ UTR of any of Tables 1-3 allows the retrotransposase to bind the template RNA. In some embodiments, a 3′ UTR of any of Tables 1-3 allows the retrotransposase to bind the template RNA. Thus, in some embodiments, a polypeptide for use in any of the systems described herein can be a polypeptide of any of Tables 1-3 herein, or a sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto. In some embodiments, the system further comprises one or both of a 5′ or 3′ untranslated region of any of Tables 1-3 herein (or a sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto), e.g., from the same transposon as the polypeptide referred to in the preceding sentence, as indicated in the same row of the same table. In some embodiments, the system comprises one or both of a 5′ or 3′ untranslated region of any of Tables 1-3 herein, e.g., a segment of the full transposon sequence that encodes an RNA that is capable of binding a retrotransposase, and/or the sub-sequence provided in the column entitled Predicted 5′ UTR or Predicted 3′ UTR.
In some embodiments, a polypeptide for use in any of the systems described herein can be a molecular reconstruction or ancestral reconstruction based upon the aligned polypeptide sequence of multiple retrotransposons. In some embodiments, a 5′ or 3′ untranslated region for use in any of the systems described herein can be a molecular reconstruction based upon the aligned 5′ or 3′ untranslated region of multiple retrotransposons. A skilled artisan can, based on the Accession numbers provided herein, align polypeptides or nucleic acid sequences, e.g., by using routine sequence analysis tools as Basic Local Alignment Search Tool (BLAST) or CD-Search for conserved domain analysis. Molecular reconstructions can be created based upon sequence consensus, e.g. using approaches described in Ivics et al., Cell 1997, 501 510; Wagstaff et al., Molecular Biology and Evolution 2013, 88-99. In some embodiments, the retrotransposon from which the 5′ or 3′ untranslated region or polypeptide is derived is a young or a recently active mobile element, as assessed via phylogenetic methods such as those described in Boissinot et al., Molecular Biology and Evolution 2000, 915-928.
Table 3 (below) shows exemplary GENE WRITER™ proteins and associated sequences from a variety of retrotransposases, identified using data mining. Column 1 indicates the family to which the retrotransposon belongs. Column 2 lists the element name. Column 3 indicates an accession number, if any. Column 4 lists an organism in which the retrotransposase is found. Column 5 lists the DNA sequence of the retrotransposon. Column 6 lists the predicted 5′ untranslated region, and column 7 lists the predicted 3′ untranslated region; both are segments of the sequence of column 5 that are predicted to allow the template RNA to bind the retrotransposase of column 8. (It is understood that columns 5-7 show the DNA sequence, and that an RNA sequence according to any of columns 5-7 would typically include uracil rather than thymidine.) Column 8 lists the predicted retrotransposase sequence encoded in the retrotransposon of column 5.
Gene Writers, e.g. Thermostable GENE WRITER™ Genome Editor Polypeptides
While not wishing to be bound by theory, in some embodments, retrotransposases that evolved in cold environments may not function as well at human body temperature. This application provides a number of thermostable GENE WRITER™ genome editor polypeptides, including proteins derived from avian retrotransposases. Exemplary avian transposase sequences in Table 3 include those of Taeniopygia guttata (zebra finch; transposon name R2-1_TG), Geospiza fortis (medium ground finch; transposon name R2-1_Gfo), Zonotrichia albicollis (white-throated sparrow; transposon name R2-1_ZA), and Tinamus guttatus (white-throated tinamou; transposon name R2-1_TGut).
Thermostability may be measured, e.g., by testing the ability of a GENE WRITER™ to polymerize DNA in vitro at a high temperature (e.g., 37° C.) and a low temberature (e.g., 25° C.). Suitable conditions for assaying in vitro DNA polymerization activity (e.g., processivity) are described, e.g., in Bibillo and Eickbush, “High Processivity of the Reverse Transcriptase from a Non-long Terminal Repeat Retrotransposon” (2002) JBC 277, 34836-34845. In some embodiments, the thermostable GENE WRITER™ polypeptide has an activity, e.g., a DNA polymerization activity, at 37° C. that is no less than 70%, 75%, 80%, 85%, 90%, or 95% of its activity at 25° C. under otherwise similar conditions.
In some embodiments, a GENE WRITER™ polypeptide (e.g., a sequence of Table 1, 2, or 3 or a sequence having at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto) is stable in a subject chosen from a mammal (e.g., human) or a bird. In some embodiments, a GENE WRITER™ polypeptide described herein is functional at 37° C. In some embodiments, a GENE WRITER™ polypeptide described herein has greater activity at 37° C. than it does at a lower temperature, e.g., at 30° C., 25° C., or 20° C. In some embodiments, a GENE WRITER™ polypeptide described herein has greater activity in a human cell than in a zebrafish cell.
In some embodiments, a GENE WRITER™ polypeptide is active in a human cell cultured at 37° C., e.g., using an assay of Example 6 or Example 7 herein.
In some embodiments, the assay comprises steps of: (1) introducing HEK293T cells into one or more wells of 6.4 mm diameter, at 10,000 cells/well, (2) incubating the cells at 37° C. for 24 hr, (3) providing a transfection mixture comprising 0.5 μl if FuGENE® HD transfection reagent and 80 ng DNA (wherein the DNA is a plasmid comprising, in order, (a) CMV promoter, (b) 100 bp of sequence homologous to the 100 bp upstream of the target site, (c) sequence encoding a 5′ untranslated region that binds the GENE WRITER™ protein, (d) sequence encoding the GENE WRITER™ protein, (e) sequence encoding a 3′ untranslated region that binds the GENE WRITER™ protein (f) 100 bp of sequence homologous to the 100 bp downstream of the target site, and (g) BGH polyadenylation sequence) and 10 μl Opti-MEM and incubating for 15 min at room temperature, (4) adding the transfection mixture to the cells, (5) incubating the cells for 3 days, and (6) assaying integration of the exogenous sequence into a target locus (e.g., rDNA) in the cell genome, e.g., wherein one or more of the preceding steps are performed as described in Example 6 herein.
In some embodiments, the GENE WRITER™ polypeptide results in insertion of the heterologous object sequence (e.g., the GFP gene) into the target locus (e.g., rDNA) at an average copy number of at least 0.01, 0.025, 0.05, 0.075, 0.1, 0.15, 0.2, 0.25, 0.3, 0.4, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 4, or 5 copies per genome. In some embodiments, a cell described herein (e.g., a cell comprising a heterologous sequence at a target insertion site) comprises the heterologous object sequence at an average copy number of at least 0.01, 0.025, 0.05, 0.075, 0.1, 0.15, 0.2, 0.25, 0.3, 0.4, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.5, 3, 4, or 5 copies per genome. In some embodiments, a GENE WRITER™ causes integration of a sequence in a target RNA with relatively few truncation events at the terminus. For instance, in some embodiments, a GENE WRITER™ protein (e.g., of SEQ ID NO: 1016) results in about 25-100%, 50-100%, 60-100%, 70-100%, 75-95%, 80%-90%, or 86.17% of integrants into the target site being non-truncated, as measured by an assay described herein, e.g., an assay of Example 6 and
In some embodiments, a system or method described herein results in insertion of the heterologous object sequence only at one target site in the genome of the target cell. Insertion can be measured, e.g., using a threshold of above 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, e.g., as described in Example 8. In some embodiments, a system or method described herein results in insertion of the heterologous object sequence wherein less than 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 10%, 20%, 30%, 40%, or 50% of insertions are at a site other than the target site, e.g., using an assay described herein, e.g., an assay of Example 8.
In some embodiments, a system or method described herein results in “scarless” insertion of the heterologous object sequence, while in some embodiments, the target site can show deletions or duplications of endogenous DNA as a result of insertion of the heterologous sequence. The mechanisms of different retrotransposons could result in different patterns of duplications or deletions in the host genome occurring during retrotransposition at the target site. In some embodiments, the system results in a scarless insertion, with no duplications or deletions in the surrounding genomic DNA. In some embodiments, the system results in a deletion of less than 1, 2, 3, 4, 5, 10, 50, or 100 bp of genomic DNA upstream of the insertion. In some embodiments, the system results in a deletion of less than 1, 2, 3, 4, 5, 10, 50, or 100 bp of genomic DNA downstream of the insertion. In some embodiments, the system results in a duplication of less than 1, 2, 3, 4, 5, 10, 50, or 100 bp of genomic DNA upstream of the insertion. In some embodiments, the system results in a duplication of less than 1, 2, 3, 4, 5, 10, 50, or 100 bp of genomic DNA downstream of the insertion.
In some embodiments, a GENE WRITER™ described herein, or a DNA-binding domain thereof, binds to its target site specifically, e.g., as measured using an assay of Example 21. In some embodiments, the GENE WRITER™ or DNA-binding domain thereof binds to its target site more strongly than to any other binding site in the human genome. For example, in some embodiments, in an assay of Example 21, the target site represents more than 50%, 60%, 70%, 80%, 90%, or 95% of binding events of the GENE WRITER™ or DNA-binding domain thereof to human genomic DNA.
Some non-LTR retrotransposons utilize two subunits to complete retrotransposition (Christensen et al PNAS 2006). In some embodiments, a retrotransposase described herein comprises two connected subunits as a single polypeptide. For instance, two wild-type retrotransposases could be joined with a linker to form a covalently “dimerized” protein (see
Based on mechanism, not all functions are required from both retrotransposase subunits. In some embodiments, the fusion protein may consist of a fully functional subunit and a second subunit lacking one or more functional domains. In some embodiments, one subunit may lack reverse transcriptase functionality. In some embodiments, one subunit may lack the reverse transcriptase domain. In some embodiments, one subunit may possess only endonuclease activity. In some embodiments, one subunit may possess only an endonuclease domain. In some embodiments, the two subunits comprising the single polypeptide may provide complimentary functions.
In some embodiments, one subunit may lack endonuclease functionality. In some embodiments, one subunit may lack the endonuclease domain. In some embodiments, one subunit may possess only reverse transcriptase activity. In some embodiments, one subunit may possess only a reverse transcriptase domain. In some embodiments, one subunit may possess only DNA-dependent DNA synthesis functionality.
In some embodiments, domains of the compositions and systems described herein (e.g., the endonuclease and reverse transcriptase domains of a polypeptide or the DNA binding domain and reverse transcriptase domains of a polypeptide) may be joined by a linker. A composition described herein comprising a linker element has the general form S1-L-S2, wherein S1 and S2 may be the same or different and represent two domain moieties (e.g., each a polypeptide or nucleic acid domain) associated with one another by the linker. In some embodiments, a linker may connect two polypeptides. In some embodiments, a linker may connect two nucleic acid molecules. In some embodiments, a linker may connect a polypeptide and a nucleic acid molecule. A linker may be a chemical bond, e.g., one or more covalent bonds or non-covalent bonds. A linker may be flexible, rigid, and/or cleavable. In some embodiments, the linker is a peptide linker. Generally, a peptide linker is at least 2, 3, 4, 5, 6, 7, 8, 9, 10 or more amino acids in length, e.g., 2-50 amino acids in length, 2-30 amino acids in length.
The most commonly used flexible linkers have sequences consisting primarily of stretches of Gly and Ser residues (“GS” linker). Flexible linkers may be useful for joining domains that require a certain degree of movement or interaction and may include small, non-polar (e.g. Gly) or polar (e.g. Ser or Thr) amino acids. Incorporation of Ser or Thr can also maintain the stability of the linker in aqueous solutions by forming hydrogen bonds with the water molecules, and therefore reduce unfavorable interactions between the linker and the other moieties. Examples of such linkers include those having the structure [GGS]≥1 or [GGGS]≥1 (SEQ ID NO: 1536). Rigid linkers are useful to keep a fixed distance between domains and to maintain their independent functions. Rigid linkers may also be useful when a spatial separation of the domains is critical to preserve the stability or bioactivity of one or more components in the agent. Rigid linkers may have an alpha helix-structure or Pro-rich sequence, (XP)n, with X designating any amino acid, preferably Ala, Lys, or Glu. Cleavable linkers may release free functional domains in vivo. In some embodiments, linkers may be cleaved under specific conditions, such as the presence of reducing reagents or proteases. In vivo cleavable linkers may utilize the reversible nature of a disulfide bond. One example includes a thrombin-sensitive sequence (e.g., PRS) between the two Cys residues. In vitro thrombin treatment of CPRSC (SEQ ID NO: 1537) results in the cleavage of the thrombin-sensitive sequence, while the reversible disulfide linkage remains intact. Such linkers are known and described, e.g., in Chen et al. 2013. Fusion Protein Linkers: Property, Design and Functionality. Adv Drug Deliv Rev. 65(10): 1357-1369. In vivo cleavage of linkers in compositions described herein may also be carried out by proteases that are expressed in vivo under pathological conditions (e.g. cancer or inflammation), in specific cells or tissues, or constrained within certain cellular compartments. The specificity of many proteases offers slower cleavage of the linker in constrained compartments.
In some embodiments the amino acid linkers are (or are homologous to) the endogenous amino acids that exist between such domains in a native polypeptide. In some embodiments the endogenous amino acids that exist between such domains are substituted but the length is unchanged from the natural length. In some embodiments, additional amino acid residues are added to the naturally existing amino acid residues between domains.
In some embodiments, the amino acid linkers are designed computationally or screened to maximize protein function (Anad et al., FEBS Letters, 587:19, 2013).
TheGENE WRITER™ systems described herein can transcribe an RNA sequence template into host target DNA sites by target-primed reverse transcription. By writing DNA sequence(s) via reverse transcription of the RNA sequence template directly into the host genome, the GENE WRITER™ system can insert an object sequence into a target genome without the need for exogenous DNA sequences to be introduced into the host cell (unlike, for example, CRISPR systems), as well as eliminate an exogenous DNA insertion step. Therefore, the GENE WRITER™ system provides a platform for the use of customized RNA sequence templates containing object sequences, e.g., sequences comprising heterologous gene coding and/or function information.
In some embodiments the template RNA encodes a GENE WRITER™ protein in cis with a heterologous object sequence. Various cis constructs were described, for example, in Kuroki-Kami et al (2019) Mobile DNA 10:23 (incorporated by reference herein in its entirety), and can be used in combination with any of the embodiments described herein. For instance, in some embodiments, the template RNA comprises a heterologous object sequence, a sequence encoding a GENE WRITER™ protein (e.g., a protein comprising (i) a reverse transcriptase domain and (ii) an endonuclease domain, e.g., as described herein), a 5′ untranslated region, and a 3′ untranslated region. The components may be included in various orders. In some embodiments, the GENE WRITER™ protein and heterologous object sequence are encoded in different directions (sense vs. anti-sense), e.g., using an arrangement shown in
The nucleic acid encoding the GENE WRITER™ polypeptide may, in some instances, be 5′ of the heterologous object sequence. For example, in some embodiments, the template RNA comprises, from 5′ to 3′, a 5′ untranslated region, a sense-encoded GENE WRITER™ polypeptide, a sense-encoded heterologous object sequence, and 3′ untranslated region. In some embodiments, the template RNA comprises, from 5′ to 3′, a 5′ untranslated region, a sense-encoded GENE WRITER™ polypeptide, anti-sense-encoded heterologous object sequence, and 3′ untranslated region.
In some embodiments, the RNA further comprises homology to the DNA target site.
It is understood that, when a template RNA is described as comprising an open reading frame or the reverse complement thereof, in some embodiments the template RNA must be converted into double stranded DNA (e.g., through reverse transcription) before the open reading frame can be transcribed and translated.
In certain embodiments, customized RNA sequence template can be identified, designed, engineered and constructed to contain sequences altering or specifying host genome function, for example by introducing a heterologous coding region into a genome; affecting or causing exon structure/alternative splicing; causing disruption of an endogenous gene; causing transcriptional activation of an endogenous gene; causing epigenetic regulation of an endogenous DNA; causing up- or down-regulation of operably liked genes, etc. In certain embodiments, a customized RNA sequence template can be engineered to contain sequences coding for exons and/or transgenes, provide for binding sites to transcription factor activators, repressors, enhancers, etc., and combinations of thereof. In other embodiments, the coding sequence can be further customized with splice acceptor sites, poly-A tails. In certain embodiments the RNA sequence can contain sequences coding for an RNA sequence template homologous to the RLE transposase, be engineered to contain heterologous coding sequences, or combinations thereof.
The template RNA may have some homology to the target DNA. In some embodiments the template RNA has at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 175, 200 or more bases of exact homology to the target DNA at the 3′ end of the RNA. In some embodiments the template RNA has at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 175, 180, or 200 or more bases of at least 50%, 60%, 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% homology to the target DNA, e.g., at the 5′ end of the template RNA. In some embodiments the template RNA has a 3′ untranslated region derived from a non-LTR retrotransposon, e.g. a non-LTR retrotransposons described herein. In some embodiments the template RNA has a 3′ region of at least 10, 15, 20, 25, 30, 40, 50, 60, 80, 100, 120, 140, 160, 180, 200 or more bases of at least 50%, 60%, 70%, 80%, 85%, 90%, 95%, 97%, 98%, 99% or 100% homology to the 3′ sequence of a non-LTR retrotransposon, e.g., a non-LTR retrotransposon described herein, e.g. a non-LTR retrotransposon in Table 1, 2, or 3. In some embodiments the template RNA has a 5′ untranslated region derived from a non-LTR retrotransposon, e.g. a non-LTR retrotransposons described herein. In some embodiments the template RNA has a 5′ region of at least 10, 15, 20, 25, 30, 40, 50, 60, 80, 100, 120, 140, 160, 180, or 200 or more bases of at least 40%, 50%, 60%, 70%, 80%, 90%, 95% or greater homology to the 5′ sequence of a non-LTR retrotransposon, e.g., a non-LTR retrotransposon described herein, e.g. a non-LTR retrotransposon described in Table 2 or 3.
The template RNA component of a GENE WRITER™ genome editing system described herein typically is able to bind the GENE WRITER™ genome editing protein of the system. In some embodiments the template RNA has a 3′ region that is capable of binding a GENE WRITER™ genome editing protein. The binding region, e.g., 3′ region, may be a structured RNA region, e.g., having at least 1, 2 or 3 hairpin loops, capable of binding the GENE WRITER™ genome editing protein of the system.
The template RNA component of a GENE WRITER™ genome editing system described herein typically is able to bind the GENE WRITER™ genome editing protein of the system. In some embodiments the template RNA has a 5′ region that is capable of binding a GENE WRITER™ genome editing protein. The binding region, e.g., 5′ region, may be a structured RNA region, e.g., having at least 1, 2 or 3 hairpin loops, capable of binding the GENE WRITER™ genome editing protein of the system. In some embodiments, the 5′ untranslated region comprises a pseudoknot, e.g., a pseudoknot that is capable of binding to the GENE WRITER™ protein.
In some embodiments, the template RNA (e.g., an untranslated region of the hairpin RNA, e.g., a 5′ untranslated region) comprises a stem-loop sequence. In some embodiments, the template RNA (e.g., an untranslated region of the hairpin RNA, e.g., a 5′ untranslated region) comprises a hairpin. In some embodiments, the template RNA (e.g., an untranslated region of the hairpin RNA, e.g., a 5′ untranslated region) comprises a helix. In some embodiments, the template RNA (e.g., an untranslated region of the hairpin RNA, e.g., a 5′ untranslated region) comprises a psuedoknot. In some embodiments the template RNA comprises a ribozyme. In some embodiments the ribozyme is similar to an hepatitis delta virus (HDV) ribozyme, e.g., has a secondary structure like that of the HDV ribozyme and/or has one or more activities of the HDV ribozyme, e.g., a self-cleavage activity. See, e.g., Eickbush et al., Molecular and Cellular Biology, 2010, 3142-3150.
In some embodiments, the template RNA (e.g., an untranslated region of the hairpin RNA, e.g., a 3′ untranslated region) comprises one or more stem-loops or helices. Exemplary structures of R2 3′ UTRs are shown, for example, in Ruschak et al. “Secondary structure models of the 3′ untranslated regions of diverse R2 RNAs” RNA. 2004 June; 10(6): 978-987, e.g., at
In some embodiments, a template RNA described herein comprises a sequence that is capable of binding to a GENE WRITER™ protein described herein. For instance, in some embodiments, the template RNA comprises an MS2 RNA sequence capable of binding to an MS2 coat protein sequence in the GENE WRITER™ protein. In some embodiments, the template RNA comprises an RNA sequence capable of binding to a B-box sequence. In some embodiments, the template RNA comprises an RNA sequence (e.g., a crRNA sequence and/or tracrRNA sequence) capable of binding to a dCas sequence in the GENE WRITER™ protein. In some embodiments, in addition to or in place of a UTR, the template RNA is linked (e.g., covalently) to a non-RNA UTR, e.g., a protein or small molecule.
In some embodiments the template RNA has a poly-A tail at the 3′ end. In some embodiments the template RNA does not have a poly-A tail at the 3′ end.
In some embodiments the template RNA has a 5′ region of at least 10, 15, 20, 25, 30, 40, 50, 60, 80, 100, 120, 140, 160, 180, 200 or more bases of at least 40%, 50%, 60%, 70%, 80%, 90%, 95% or greater homology to the 5′ sequence of a non-LTR retrotransposon, e.g., a non-LTR retrotransposon described herein.
The template RNA of the system typically comprises an object sequence for insertion into a target DNA. The object sequence may be coding or non-coding.
In some embodiments a system or method described herein comprises a single template RNA. In some embodiments a system or method described herein comprises a plurality of template RNAs.
In some embodiments, the object sequence may contain an open reading frame. In some embodiments the template RNA has a Kozak sequence. In some embodiments the template RNA has an internal ribosome entry site. In some embodiments the template RNA has a self-cleaving peptide such as a T2A or P2A site. In some embodiments the template RNA has a start codon. In some embodiments the template RNA has a splice acceptor site. In some embodiments the template RNA has a splice donor site. In some embodiments the template RNA has a microRNA binding site downstream of the stop codon. In some embodiments the template RNA has a polyA tail downstream of the stop codon of an open reading frame. In some embodiments the template RNA comprises one or more exons. In some embodiments the template RNA comprises one or more introns. In some embodiments the template RNA comprises a eukaryotic transcriptional terminator. In some embodiments the template RNA comprises an enhanced translation element or a translation enhancing element. In some embodiments the RNA comprises the human T-cell leukemia virus (HTLV-1) R region. In some embodiments the RNA comprises a posttranscriptional regulatory element that enhances nuclear export, such as that of Hepatitis B Virus (HPRE) or Woodchuck Hepatitis Virus (WPRE). In some embodiments, in the template RNA, the heterologous object sequence encodes a polypeptide and is coded in an antisense direction with respect to the 5′ and 3′ UTR. In some embodiments, in the template RNA, the heterologous object sequence encodes a polypeptide and is coded in a sense direction with respect to the 5′ and 3′ UTR.
In some embodiments, a nucleic acid described herein (e.g., a template RNA or a DNA encoding a template RNA) comprises a microRNA binding site. In some embodiments, the microRNA binding site is used to increase the target-cell specificity of a GENE WRITER™ system. For instance, the microRNA binding site can be chosen on the basis that is is recognized by a miRNA that is present in a non-target cell type, but that is not present (or is present at a reduced level relative to the non-target cell) in a target cell type. Thus, when the template RNA is present in a non-target cell, it would be bound by the miRNA, and when the template RNA is present in a target cell, it would not be bound by the miRNA (or bound but at reduced levels relative to the non-target cell). While not wishing to be bound by theory, binding of the miRNA to the template RNA may interfere with insertion of the heterologous object sequence into the genome. Accordingly, the heterologous object sequence would be inserted into the genome of target cells more efficiently than into the genome of non-target cells. A system having a microRNA binding site in the template RNA (or DNA encoding it) may also be used in combination with a nucleic acid encoding a GENE WRITER™ polypeptide, wherein expression of the GENE WRITER™ polypeptide is regulated by a second microRNA binding site, e.g., as described herein, e.g., in the section entitled “Polypeptide component of GENE WRITER™ gene editor system”.
In some embodiments, the object sequence may contain a non-coding sequence. For example, the template RNA may comprise a promoter or enhancer sequence. In some embodiments the template RNA comprises a tissue specific promoter or enhancer, each of which may be unidirectional or bidirectional. In some embodiments the promoter is an RNA polymerase I promoter, RNA polymerase II promoter, or RNA polymerase III promoter. In some embodiments the promoter comprises a TATA element. In some embodiments the promoter comprises a B recognition element. In some embodiments the promoter has one or more binding sites for transcription factors. In some embodiments the non-coding sequence is transcribed in an antisense-direction with respect to the 5′ and 3′ UTR. In some the non-coding sequence is transcribed in a sense direction with respect to the 5′ and 3′ UTR.
In some embodiments, a nucleic acid described herein (e.g., a template RNA or a DNA encoding a template RNA) comprises a promoter sequence, e.g., a tissue specific promoter sequence. In some embodiments, the tissue-specific promoter is used to increase the target-cell specificity of a GENE WRITER™ system. For instance, the promoter can be chosen on the basis that it is active in a target cell type but not active in (or active at a lower level in) a non-target cell type. Thus, even if the promoter integrated into the genome of a non-target cell, it would not drive expression (or only drive low level expression) of an integrated gene. A system having a tissue-specific promoter sequence in the template RNA may also be used in combination with a microRNA binding site, e.g., in the template RNA or a nucleic acid encoding a GENE WRITER™ protein, e.g., as described herein. A system having a tissue-specific promoter sequence in the template RNA may also be used in combination with a DNA encoding a GENE WRITER™ polypeptide, driven by a tissue-specific promoter, e.g., to achieve higher levels of GENE WRITER™ protein in target cells than in non-target cells.
In some embodiments the template RNA comprises a microRNA sequence, a siRNA sequence, a guide RNA sequence, a piwi RNA sequence.
In some embodiments the template RNA comprises a site that coordinates epigenetic modification. In some embodiments the template RNA comprises an element that inhibits, e.g., prevents, epigenetic silencing. In some embodiments the template RNA comprises a chromatin insulator. For example, the template RNA comprises a CTCF site or a site targeted for DNA methylation.
In order to promote higher level or more stable gene expression, the template RNA may include features that prevent or inhibit gene silencing. In some embodiments, these features prevent or inhibit DNA methylation. In some embodiments, these features promote DNA demethylation. In some embodiments, these features prevent or inhibit histone deacetylation. In some embodiments, these features prevent or inhibit histone methylation. In some embodiments, these features promote histone acetylation. In some embodiments, these features promote histone demethylation. In some embodiments, multiple features may be incorporated into the template RNA to promote one or more of these modifications. CpG dinculeotides are subject to methylation by host methyl transferases. In some embodiments, the template RNA is depleted of CpG dinucleotides, e.g., does not comprise CpG nucleotides or comprises a reduced number of CpG dinucleotides compared to a corresponding unaltered sequence. In some embodiments, the promoter driving transgene expression from integrated DNA is depleted of CpG dinucleotides.
In some embodiments the template RNA comprises a gene expression unit composed of at least one regulatory region operably linked to an effector sequence. The effector sequence may be a sequence that is transcribed into RNA (e.g., a coding sequence or a non-coding sequence such as a sequence encoding a micro RNA).
In some embodiments the object sequence of the template RNA is inserted into a target genome in an endogenous intron. In some embodiments the object sequence of the template RNA is inserted into a target genome and thereby acts as a new exon. In some embodiments the insertion of the object sequence into the target genome results in replacement of a natural exon or the skipping of a natural exon.
In some embodiments the object sequence of the template RNA is inserted into the target genome in a genomic safe harbor site, such as AAVS1, CCR5, or ROSA26. In some embodiment the object sequence of the template RNA is added to the genome in an intergenic or intragenic region. In some embodiments the object sequence of the template RNA is added to the genome 5′ or 3′ within 0.1 kb, 0.25 kb, 0.5 kb, 0.75, kb, 1 kb, 2 kb, 3 kb, 4 kb, 5 kb, 7.5 kb, 10 kb, 15 kb, 20 kb, 25 kb, 50, 75 kb, or 100 kb of an endogenous active gene. In some embodiments the object sequence of the template RNA is added to the genome 5′ or 3′ within 0.1 kb, 0.25 kb, 0.5 kb, 0.75, kb, 1 kb, 2 kb, 3 kb, 4 kb, 5 kb, 7.5 kb, 10 kb, 15 kb, 20 kb, 25 kb, 50, 75 kb, or 100 kb of an endogenous promoter or enhancer. In some embodiments the object sequence of the template RNA can be, e.g., 50-50,000 base pairs (e.g., between 50-40,000 bp, between 500-30,000 bp between 500-20,000 bp, between 100-15,000 bp, between 500-10,000 bp, between 50-10,000 bp, between 50-5,000 bp. In some embodiments, the heterologous object sequence is less than 1,000, 1,300, 1500, 2,000, 3,000, 4,000, 5,000, or 7,500 nucleotides in length.
In some embodiments the genomic safe harbor site is a NATURAL HARBOR™ site. In some embodiments the NATURAL HARBOR™ site is ribosomal DNA (rDNA). In some embodiments the NATURAL HARBOR™ site is 5S rDNA, 18S rDNA, 5.8S rDNA, or 28S rDNA. In some embodiments the NATURAL HARBOR™ site is the Mutsu site in 5S rDNA. In some embodiments the NATURAL HARBOR™ site is the R2 site, the R5 site, the R6 site, the R4 site, the R1 site, the R9 site, or the RT site in 28S rDNA. In some embodiments the NATURAL HARBOR™ site is the R8 site or the R7 site in 18S rDNA. In some embodiments the NATURAL HARBOR™ site is DNA encoding transfer RNA (tRNA). In some embodiments the NATURAL HARBOR™ site is DNA encoding tRNA-Asp or tRNA-Glu. In some embodiments the NATURAL HARBOR™ site is DNA encoding spliceosomal RNA. In some embodiments the NATURAL HARBOR™ site is DNA encoding small nuclear RNA (snRNA) such as U2 snRNA.
Thus, in some aspects, the present disclosure provides a method of inserting a heterologous object sequence into a NATURAL HARBOR™ site. In some embodimetns, the method comprises using a GENE WRITER™ system described herein, e.g., using a polypeptide of any of Tables 1-3 or a polypeptide having sequence similarity thereto, e.g., at least 80%, 85%, 90%, or 95% identity thereto. In some embodiments, the method comprises using an enzyme, e.g., a retrotransposase, to insert the heterologous object sequence into the NATURAL HARBOR™ site. In some aspects, the present disclosure provides a host human cell comprising a heterologous object sequence (e.g., a sequence encoding a therapeutic polypeptide) situated at a NATURAL HARBOR™ site in the genome of the cell. In some embodiments, the NATURAL HARBOR™ site is a site described in Table 4 below. In some embodiments, the heterologous object sequence is inserted within 20, 50, 100, 150, 200, 250, 500, or 1000 base pairs of a sequence shown in Table 4. In some embodiments, the heterologous object sequence is inserted within 0.1 kb, 0.25 kb, 0.5 kb, 0.75, kb, 1 kb, 2 kb, 3 kb, 4 kb, 5 kb, 7.5 kb, 10 kb, 15 kb, 20 kb, 25 kb, 50, 75 kb, or 100 kb of a sequence shown in Table 4. In some embodiments, the heterologous object sequence is inserted into a site having at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity to a sequence shown in Table 4. In some embodiments, the heterologous object sequence is inserted within 20, 50, 100, 150, 200, 250, 500, or 1000 base pairs, or within 0.1 kb, 0.25 kb, 0.5 kb, 0.75, kb, 1 kb, 2 kb, 3 kb, 4 kb, 5 kb, 7.5 kb, 10 kb, 15 kb, 20 kb, 25 kb, 50, 75 kb, or 100 kb, of a site having at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity to a sequence shown in Table 4. In some embodiments, the heterologous object sequence is inserted within a gene indicated in Column 5 of Table 4, or within 20, 50, 100, 150, 200, 250, 500, or 1000 base pairs, or within 0.1 kb, 0.25 kb, 0.5 kb, 0.75, kb, 1 kb, 2 kb, 3 kb, 4 kb, 5 kb, 7.5 kb, 10 kb, 15 kb, 20 kb, 25 kb, 50, 75 kb, or 100 kb, of the gene.
In some embodiments, a system or method described herein results in insertion of a heterologous sequence into a target site in the human genome. In some embodiments, the target site in the human genome has sequence similarity to the corresponding target site of the corresponding wild-type retrotransposase (e.g., the retrotransposase from which the GENE WRITER™ was derived) in the genome of the organism to which it is native. For instance, in some embodiments, the identity between the 40 nucleotides of human genome sequence centered at the insertion site and the 40 nucleotides of native organism genome sequence centered at the insertion site is less than 99.5%, 99%, 98%, 97%, 96%, 95%, 90%, 85%, 80%, 75%, 70%, 60%, or 50%, or is between 50-60%, 60-70%, 70-80%, 80-90%, or 90-100%. In some embodiments, the identity between the 100 nucleotides of human genome sequence centered at the insertion site and the 100 nucleotides of native organism genome sequence centered at the insertion site is less than 99.5%, 99%, 98%, 97%, 96%, 95%, 90%, 85%, 80%, 75%, 70%, 60%, or 50%, or is between 50-60%, 60-70%, 70-80%, 80-90%, or 90-100%. In some embodiments, the identity between the 500 nucleotides of human genome sequence centered at the insertion site and the 500 nucleotides of native organism genome sequence centered at the insertion site is less than 99.5%, 99%, 98%, 97%, 96%, 95%, 90%, 85%, 80%, 75%, 70%, 60%, or 50%, or is between 50-60%, 60-70%, 70-80%, 80-90%, or 90-100%.
As will be appreciated by one of skill, methods of designing and constructing nucleic acid constructs and proteins or polypeptides (such as the systems, constructs and polypeptides described herein) are routine in the art. Generally, recombinant methods may be used. See, in general, Smales & James (Eds.), Therapeutic Proteins: Methods and Protocols (Methods in Molecular Biology), Humana Press (2005); and Crommelin, Sindelar & Meibohm (Eds.), Pharmaceutical Biotechnology: Fundamentals and Applications, Springer (2013). Methods of designing, preparing, evaluating, purifying and manipulating nucleic acid compositions are described in Green and Sambrook (Eds.), Molecular Cloning: A Laboratory Manual (Fourth Edition), Cold Spring Harbor Laboratory Press (2012).
Exemplary methods for producing a therapeutic pharmaceutical protein or polypeptide described herein involve expression in mammalian cells, although recombinant proteins can also be produced using insect cells, yeast, bacteria, or other cells under control of appropriate promoters. Mammalian expression vectors may comprise non-transcribed elements such as an origin of replication, a suitable promoter, and other 5′ or 3′ flanking non-transcribed sequences, and 5′ or 3′ non-translated sequences such as necessary ribosome binding sites, a polyadenylation site, splice donor and acceptor sites, and termination sequences. DNA sequences derived from the SV40 viral genome, for example, SV40 origin, early promoter, splice, and polyadenylation sites may be used to provide other genetic elements required for expression of a heterologous DNA sequence. Appropriate cloning and expression vectors for use with bacterial, fungal, yeast, and mammalian cellular hosts are described in Green & Sambrook, Molecular Cloning: A Laboratory Manual (Fourth Edition), Cold Spring Harbor Laboratory Press (2012).
Various mammalian cell culture systems can be employed to express and manufacture recombinant protein. Examples of mammalian expression systems include CHO, COS, HEK293, HeLA, and BHK cell lines. Processes of host cell culture for production of protein therapeutics are described in Zhou and Kantardjieff (Eds.), Mammalian Cell Cultures for Biologics Manufacturing (Advances in Biochemical Engineering/Biotechnology), Springer (2014). Compositions described herein may include a vector, such as a viral vector, e.g., a lentiviral vector, encoding a recombinant protein. In some embodiments, a vector, e.g., a viral vector, may comprise a nucleic acid encoding a recombinant protein.
Purification of protein therapeutics is described in Franks, Protein Biotechnology: Isolation, Characterization, and Stabilization, Humana Press (2013); and in Cutler, Protein Purification Protocols (Methods in Molecular Biology), Humana Press (2010).
By integrating coding genes into a RNA sequence template, the GENE WRITER™ system can address therapeutic needs, for example, by providing expression of a therapeutic transgene in individuals with loss-of-function mutations, by replacing gain-of-function mutations with normal transgenes, by providing regulatory sequences to eliminate gain-of-function mutation expression, and/or by controlling the expression of operably linked genes, transgenes and systems thereof. In certain embodiments, the RNA sequence template encodes a promotor region specific to the therapeutic needs of the host cell, for example a tissue specific promotor or enhancer. In still other embodiments, a promotor can be operably linked to a coding sequence.
In embodiments, the GENE WRITER™ gene editor system can provide therapeutic transgenes expressing, e.g., replacement blood factors or replacement enzymes, e.g., lysosomal enzymes. For example, the compositions, systems and methods described herein are useful to express, in a target human genome, agalsidase alpha or beta for treatment of Fabry Disease; imiglucerase, taliglucerase alfa, velaglucerase alfa, or alglucerase for Gaucher Disease; sebelipase alpha for lysosomal acid lipase deficiency (Wolman disease/CESD); laronidase, idursulfase, elosulfase alpha, or galsulfase for mucopolysaccharidoses; alglucosidase alpha for Pompe disease. For example, the compositions, systems and methods described herein are useful to express, in a target human genome factor I, II, V, VII, X, XI, XII or XIII for blood factor deficiencies.
In some embodiments, the heterologous object sequence encodes an intracellular protein (e.g., a cytoplasmic protein, a nuclear protein, an organellar protein such as a mitochondrial protein or lysosomal protein, or a membrane protein). In some embodiments, the heterologous object sequence encodes a membrane protein, e.g., a membrane protein other than a CAR, and/or an endogenous human membrane protein. In some embodiments, the heterologous object sequence encodes an extracellular protein. In some embodiments, the heterologous object sequence encodes an enzyme, a structural protein, a signaling protein, a regulatory protein, a transport protein, a sensory protein, a motor protein, a defense protein, or a storage protein.
The composition and systems described herein may be used in vitro or in vivo. In some embodiments the system or components of the system are delivered to cells (e.g., mammalian cells, e.g., human cells), e.g., in vitro or in vivo. In some embodiments, the cells are eukaryotic cells, e.g., cells of a multicellular organism, e.g., an animal, e.g., a mammal (e.g., human, swine, bovine) a bird (e.g., poultry, such as chicken, turkey, or duck), or a fish. In some embodiments, the cells are non-human animal cells (e.g., a laboratory animal, a livestock animal, or a companion animal). In some embodiments, the cell is a stem cell (e.g., a hematopoietic stem cell), a fibroblast, or a T cell. In some embodiments, the cell is a non-dividing cell, e.g., a non-dividing fibroblast or non-dividing T cell. In some embodiments, the cell is an HSC and p53 is not upregulated or is upregulated by less than 10%, 5%, 2%, or 1%, e.g., as determined according to the method described in Example 30. The skilled artisan will understand that the components of the GENE WRITER™ system may be delivered in the form of polypeptide, nucleic acid (e.g., DNA, RNA), and combinations thereof.
For instance, delivery can use any of the following combinations for delivering the retrotransposase (e.g., as DNA encoding the retrotransposase protein, as RNA encoding the retrotransposase protein, or as the protein itself) and the template RNA (e.g., as DNA encoding the RNA, or as RNA):
As indicated above, in some embodiments, the DNA or RNA that encodes the retrotransposase protein is delivered using a virus, and in some embodiments, the template RNA (or the DNA encoding the template RNA) is delivered using a virus.
In one embodiments the system and/or components of the system are delivered as nucleic acid. For example, the GENE WRITER™ polypeptide may be delivered in the form of a DNA or RNA encoding the polypeptide, and the template RNA may be delivered in the form of RNA or its complementary DNA to be transcribed into RNA. In some embodiments the system or components of the system are delivered on 1, 2, 3, 4, or more distinct nucleic acid molecules. In some embodiments the system or components of the system are delivered as a combination of DNA and RNA. In some embodiments the system or components of the system are delivered as a combination of DNA and protein. In some embodiments the system or components of the system are delivered as a combination of RNA and protein. In some embodiments the GENE WRITER™ genome editor polypeptide is delivered as a protein.
In some embodiments the system or components of the system are delivered to cells, e.g. mammalian cells or human cells, using a vector. The vector may be, e.g., a plasmid or a virus. In some embodiments delivery is in vivo, in vitro, ex vivo, or in situ. In some embodiments the virus is an adeno associated virus (AAV), a lentivirus, an adenovirus. In some embodiments the system or components of the system are delivered to cells with a viral-like particle or a virosome. In some embodiments the delivery uses more than one virus, viral-like particle or virosome.
In one embodiment, the compositions and systems described herein can be formulated in liposomes or other similar vesicles. Liposomes are spherical vesicle structures composed of a uni- or multilamellar lipid bilayer surrounding internal aqueous compartments and a relatively impermeable outer lipophilic phospholipid bilayer. Liposomes may be anionic, neutral or cationic. Liposomes are biocompatible, nontoxic, can deliver both hydrophilic and lipophilic drug molecules, protect their cargo from degradation by plasma enzymes, and transport their load across biological membranes and the blood brain barrier (BBB) (see, e.g., Spuch and Navarro, Journal of Drug Delivery, vol. 2011, Article ID 469679, 12 pages, 2011 for review).
Vesicles can be made from several different types of lipids; however, phospholipids are most commonly used to generate liposomes as drug carriers. Methods for preparation of multilamellar vesicle lipids are known in the art (see for example U.S. Pat. No. 6,693,086, the teachings of which relating to multilamellar vesicle lipid preparation are incorporated herein by reference). Although vesicle formation can be spontaneous when a lipid film is mixed with an aqueous solution, it can also be expedited by applying force in the form of shaking by using a homogenizer, sonicator, or an extrusion apparatus (see, e.g., Spuch and Navarro, Journal of Drug Delivery, vol. 2011, Article ID 469679, 12 pages, 2011 for review). Extruded lipids can be prepared by extruding through filters of decreasing size, as described in Templeton et al., Nature Biotech, 15:647-652, 1997, the teachings of which relating to extruded lipid preparation are incorporated herein by reference.
Lipid nanoparticles are another example of a carrier that provides a biocompatible and biodegradable delivery system for the pharmaceutical compositions described herein. Nanostructured lipid carriers (NLCs) are modified solid lipid nanoparticles (SLNs) that retain the characteristics of the SLN, improve drug stability and loading capacity, and prevent drug leakage. Polymer nanoparticles (PNPs) are an important component of drug delivery. These nanoparticles can effectively direct drug delivery to specific targets and improve drug stability and controlled drug release. Lipid-polymer nanoparticles (PLNs), a new type of carrier that combines liposomes and polymers, may also be employed. These nanoparticles possess the complementary advantages of PNPs and liposomes. A PLN is composed of a core-shell structure; the polymer core provides a stable structure, and the phospholipid shell offers good biocompatibility. As such, the two components increase the drug encapsulation efficiency rate, facilitate surface modification, and prevent leakage of water-soluble drugs. For a review, see, e.g., Li et al. 2017, Nanomaterials 7, 122.
Exosomes can also be used as drug delivery vehicles for the compositions and systems described herein. For a review, see Ha et al. July 2016. Acta Pharmaceutica Sinica B. Volume 6, Issue 4, Pages 287-296.
A GENE WRITER™ system can be introduced into cells, tissues and multicellular organisms. In some embodiments the system or components of the system are delivered to the cells via mechanical means or physical means.
Formulation of protein therapeutics is described in Meyer (Ed.), Therapeutic Protein Drug Products: Practical Approaches to formulation in the Laboratory, Manufacturing, and the Clinic, Woodhead Publishing Series (2012).
All publications, patent applications, patents, and other publications and references (e.g., sequence database reference numbers) cited herein are incorporated by reference in their entirety. For example, all GENBANK™, UNIGENE™, and ENTREZ™ sequences referred to herein, e.g., in any Table herein, are incorporated by reference. Unless otherwise specified, the sequence accession numbers specified herein, including in any Table herein, refer to the database entries current as of Aug. 27, 2018. When one gene or protein references a plurality of sequence accession numbers, all of the sequence variants are encompassed.
The invention is further illustrated by the following examples. The examples are provided for illustrative purposes only and are not to be construed as limiting the scope or content of the invention in any way.
This example describes a GENE WRITER™ genome editing system delivered to a mammalian cell for site-specific insertion of exogenous DNA into a mammalian cell genome.
In this example, the polypeptide component of the GENE WRITER™ system is the R2Bm protein from Bombyx mori and the template RNA component is RNA for the R2Bm retrotransposase from Bombyx mori containing a mutation in the reverse transcriptase domain that renders the retrotransposase inactive.
HEK293T cells are transfected with the following test agents:
After transfection, HEK293T cells are cultured for at least 4 days and then assayed for site-specific genome editing. Genomic DNA is isolated from each group of HEK293 cells. PCR is conducted with primers that flank the R2Bm integration site in 28s rRNA genes. The PCR product is run on an agarose gel to measure the length of the amplified DNA.
A PCR product of the expected length, indicative of a successful GENE WRITING™ genome editing event that inserts the sequence for the mutated R2Bm retrotransposase into the target genome, is observed only in cells that were transfected with the complete GENE WRITER™ system of group 4 above.
This example describes a GENE WRITER™ genome editing system delivered to an insect cell at a specific target site of the genome.
In this example, the polypeptide component of the GENE WRITER™ system is derived from R2Bm of Bombyx mori, which is modified by replacing its DNA binding domain in the amino terminus of the polypeptide with a heterologous zinc-finger DNA binding domain. The zinc finger DNA binding domain is known to bind to DNA in the BmBLOS2 loci of B. mori cells (Takasu et al., insect Biochemistry and Molecular Biology 40(10): 759-765, 2010). The template RNA is RNA for the R2Bm retrotransposase from Bombyx mori containing a mutation in the reverse transcriptase domain that renders the retrotransposase inactive. Furthermore, the template RNA is modified at the 5′ end to have 180 bases of homology to the target DNA site.
B. mori insect cell lines are transfected with the following test agents:
After transfection, the cells are cultured for at least 4 days and assayed for site-specific GENE WRITING™ genome editing. Genomic DNA is isolated from the cells and PCR is conducted with primers that flank the target integration site in the genome. The PCR product is run on an agarose gel to measure the length of DNA. A PCR product of the expected length, indicative of a successful GENE WRITING™ genome editing event that inserts the sequence for the mutated R2Bm retrotransposase into the target insect cell genome, is observed only in cells that were transfected with the complete GENE WRITER™ system of group 4 above.
This example describes a GENE WRITER™ genome editor system used to insert a heterologous sequence into a specific site of the mammalian genome.
In this example, the polypeptide of the system is the R2Bm protein from Bombyx mori and the template RNA component is RNA coding for the GFP protein and flanked at the 5′ end by the 5′ UTR and at the 3′ end by the 3′ UTR of the R2Bm retrotransposase from Bombyx mori. The GFP gene has an internal ribosomal entry site upstream of its start codon and a polyA tail downstream of its stop codon.
HEK293 cells are transfected with the following test agents:
After transfection, HEK293 cells are cultured for at least 4 days and then assayed for a site-specific GENE WRITING™ genome editing event. Genomic DNA is isolated from the HEK293 cells and PCR is conducted with primers that flank the R2Bm integration site in 28s rRNA genes. The PCR product is run on an agarose gel to measure the length of DNA. A PCR product of the expected length, indicative of a successful GENE WRITING™ genome editing event, is detected in cells transfected with the test agent of group 4 (complete GENE WRITER™ system). This result demonstrates that a GENE WRITING™ genome editing system can insert a novel transgene into the mammalian cell genome.
The transfected cells are cultured for a further 10 days, and after multiple cell culture passages are assayed for GFP expression via flow cytometry. The percent of cells that are GFP positive from each cell population are calculated. GFP positive cells are detected in the population of HEK293 cells that were transfected with the test agent of group 4 (complete GENE WRITER™ system). This result demonstrates that the novel transgene written into the mammalian cell genome is expressed.
This example describes the making and using of a GENE WRITER™ genome editor to insert a heterologous gene expression unit into the mammalian genome.
In this example, the polypeptide of the GENE WRITER™ system is derived from the R2Bm polypeptide of Bombyx mori as modified by replacing its DNA binding domain in the amino terminus of the polypeptide with a heterologous zinc-finger DNA binding domain. The zinc finger DNA binding domain is known to bind to DNA in the AAVS1 locus of human cells (Hockemeyer et al., Nature Biotechnology 27(9): 851-857, 2009). The template RNA comprises a gene expression unit. A gene expression unit comprises at least one regulatory sequence operably linked to at least one coding sequence. In this example, the regulatory sequences include the CMV promoter and enhancer, an enhanced translation element, and a WPRE. The coding sequence is the GFP open reading frame. The gene expression unit is flanked at the 5′ end by 180 bases of homology to the target DNA site and at the 3′ end by the 3′ UTR of the R2Bm retrotransposase from Bombyx mori.
HEK293 cells are transfected with the following test agents:
After transfection, HEK293 cells are cultured for at least 4 days and assayed for site-specific GENE WRITING™ genome editing. Genomic DNA is isolated from the HEK293 cells and PCR is conducted with primers that flank the target integration site in the genome. The PCR product is run on an agarose gel to measure the length of DNA. A PCR product of the expected length, indicative of a successful GENE WRITING™ genome editing event, is detected in cells transfected with the test agent of group 4 (complete GENE WRITER™ system).
The transfected cells are cultured for a further 10 days, and after multiple cell culture passages are assayed for GFP expression via flow cytometry. The percent of cells that are GFP positive from each cell population are calculated. GFP positive cells are detected in the population of HEK293 cells that were transfected with group 4 test agent, demonstrating that a gene expression unit added into the mammalian cell genome via GENE WRITING™ genome editing is expressed.
This example describes the making and use of a GENE WRITING™ genome editing system to add a heterologous sequence into an intronic region to act as a splice acceptor for an upstream exon.
The target integration site is the first intron of the albumin locus. Splicing into the first intron a new exon containing a splice acceptor site at the 5′ end and a polyA tail at the 3′ end will result in a mature mRNA containing the first natural exon of the albumin locus spliced to the new exon. Because the first exon of albumin is removed upon protein processing, the cell expressing the newly formed gene unit will secrete a mature protein comprising only the new exon.
In this example, the GENE WRITER™ genome editor polypeptide is derived from the R2Bm GENE WRITER™ genome editor of Bombyx mori as modified by replacing the DNA binding domain in the amino terminus of the polypeptide with a heterologous zinc-finger DNA binding domain. The zinc finger DNA binding domain is known to bind tightly to the albumin locus in the first intron as described in Sarma et al., Blood 126, 15: 1777-1784, 2015. The template RNA is RNA coding for EPO with a splice acceptor site immediately 5′ to the first amino acid of mature EPO (the start codon and signal peptide is removed) and a 3′ polyA tail downstream of the stop codon. The EPO RNA is further flanked at the 5′ end by 180 bases of homology to target DNA site and at the 3′ end by the 3′ UTR of the R2Bm retrotransposase from Bombyx mori.
HEK293 cells are transfected with the following test agents:
After transfection, HEK293 cells are cultured for at least 4 days and assayed for site-specific GENE WRITING™ genome editing and appropriate mRNA processing. Genomic DNA is isolated from the HEK293 cells. Reverse transcription-PCR is conducted to measure the mature mRNA containing the first natural exon of the albumin locus and the new exon. The RT-PCR reaction is conducted with forward primers that bind to the first natural exon of the albumin locus and with reverse primers that bind to EPO. The RT-PCR product is run on an agarose gel to measure the length of DNA. A PCR product of the expected length is detected in cells transfected with the test agent of group 4, indicative of a successful GENE WRITING™ genome editing event and a successful splice event. This result demonstrates that a GENE WRITING™ genome editing system can add a heterologous sequence encoding a gene into an intronic region to act as a splice acceptor for the upstream exon.
The transfected cells are cultured for a further 10 days, and after multiple cell culture passages are assayed for EPO secretion in the cell supernatant. The amount of EPO in the supernatant is measured via an EPO ELISA kit. EPO is detected in HEK293 cells that were transfected with the test agent of group 4, demonstrating that a heterologous sequence can be added into an intronic region via GENE WRITING™ genome editing, to act as a splice acceptor for the upstream exon and is actively expressed.
This example describes targeted integration of the R2Tg retrotransposon element (see first row of Table 3 herein) to mammalian cells via DNA or RNA delivery.
R2Tg is an endogenous retrotransposon from the zebra finch (Taenopygia guttata). Because non-LTR R2 elements are not present in the human genome and are thought to be highly site-specific, the ability of R2Tg to accurately and efficiently integrate itself into the human genome would demonstrate the capability to perform genomic targeted integration and possibly enable human gene therapy.
In the DNA delivery method, plasmid harboring R2Tg (PLV014) was designed and synthesized such that the R2Tg element was codon optimized and flanked by its native un-translated regions (UTRs), with or without further flanking by 100 bp homology to the rDNA target locus. The R2Tg element expression was driven by the mammalian CMV promoter. Further, a lbp deletion mutant (678*) having a frameshift in the coding sequence of the retrotransposase was constructed as an inactivated control (“frameshift mutant”). Each plasmid was introduced into HEK393T cells via FuGENE® HD transfection reagent. HEK293T cells were seeded in 96-well plate, 10,000 cells/well 24 hr before transfection. On the transfection day, 0.5 μl transfection reagent and 80 ng DNA was mixed in 10 μl Opti-MEM and incubated for 15 min at room temperature. Then the transfection mixture was added to the medium of the seeded cells. 3 days after transfection, genomic DNA was extracted for retrotransposition assays.
Next, integration of the R2Tg transposase into the human genome was assessed. Based on homology to the finch genome, a putative integration site in human rDNA was tested. Advanced MISEQ™ and ddPCR assays were used to assess integration.
Bias in MISEQ™ library construction was eliminated by introducing random unique molecular indices (UMIs) into initial PCRs (
ddPCR was next performed to confirm integration and assess integration efficiency. A Taqman probe was designed to the 3′UTR portion of the R2Tg element. A forward primer was synthesized to bind directly upstream of the probe, and a reverse primer was synthesized to bind the rDNA. Therefore, amplification of the expected product across the integration junction degrades the probe and creates a fluorescent signal. ddPCR was performed on several replicate experiments of the above plasmids to determine the average copy number of the R2Tg integration event. The results of ddPCR copy number analysis (in comparison to reference gene RPP30) are shown in
In the RNA delivery method, R2Tg RNA (RNAV019) was designed such that the R2Tg element was codon optimized and flanked by its native untranslated regions (UTRs). More specifically, the construct includes, in order: a T7 promoter, a 5′ 28S target homology region 100 nucleotides in length, a R2Tg wild-type 5′ UTR, the R2Tg codon-optimized coding sequence, a R2Tg wild type 3′ UTR, and a 3′ 28S target homology region 100 nucleotides in length. The 100 bp 28S homology sequences were added outside of the UTRs to enhance the integration. R2Tg RNA was synthesized, and cap and polyA tail were added. The R2Tg element transcription was driven by the T7 promoter. The RNA was introduced into HEK393T cells via Lipofectamine™ RNAiMAX or TransIT®-mRNA transfection reagent with series of RNA dosages. HEK293T cells were seeded in 96-well plate 24 hr before transfection. On the transfection day, transfection reagent and RNA were mixed in 10 μl Opti-MEM, and the transfection mixture was added to the medium of the seeded cells. 3 days after transfection, genomic DNA was extracted to measure retrotransposition efficiency using ddPCR with the same design as the DNA delivery.
The results of ddPCR copy number analysis (normalized to reference gene RPP30) are shown in
This example describes the delivery of a transgene to human cells by utilizing the R2Tg retrotransposon system with multiple delivery machineries, including RNA-mediated delivery of a heterologous object sequence to human cells by utilizing the R2Tg retrotransposon system.
R2 proteins recognize their template RNA structure in untranslated regions (UTRs) of each element to form ribonucleoprotein particles, which serve as the intermediates of downstream integration into a host genome. Therefore, the decoupling of UTRs from their native context and the introduction of UTRs into alternate exogenous sequence was engineered to deliver into the genome a desired nucleic acid using R2Tg machinery.
Trans-transgene integration was tested by constructing 1) R2Tg coding sequence and 2) transgene cassette flanked by R2Tg UTR sequences and 100 bp homology to 28S rDNA into separate driver and transgene plasmids, respectively.
Similar to the trans-transgene delivery with plasmids, RNA delivery was performed by constructing an amplicon of the coding sequence of R2Tg preceded by the T7 promoter sequence. The constructed amplicons contained the experimental R2Tg element as well as the 1 bp deletion frameshift mutant control. Separately, an amplicon was constructed that contained exogenous sequence coding for GFP and an EGF1-alpha reporter that was flanked regions sufficient to drive integration into the genome by R2Tg. More specifically, the construct included: a T7 promoter driving transcription of the RNA, wherein the RNA comprises, from 5′ to 3′, (a) a 5′ 28S homology region of 10 nt in length, (b) a 5′ untranslated region, (c) an anti-sense TKpA polyA sequence, (d) an anti-sense heterologous object sequence that encodes GFP, (e) an anti-sense Kozak sequence, (f) an anti-sense EF1 alpha promoter, (g) a 3′ untranslated region that binds the GENE WRITER™ protein, and (h) a 3′ 28S homology region of 10 nt in length. Each RNA was transcribed via the New England Biolabs HiScribe T7 ARCA kit and purified via Zymo RNA clean and concentrator.
The resulting heterologous object RNA and R2Tg RNA (either the experiment R2Tg element or frameshift mutant) were introduced into human HEK293T cells via TransIT®-mRNA Transfection Kit at 1:1 molar ratio. HEK293T cells were seeded in 96-well plate, 40,000 cells/well 24 hr before transfection. On the transfection day, 1 μl transfection reagent and 500 ng total RNA was mixed in 10 μl Opti-MEM and incubated for 5 min at room temperature. Then the transfection mixture was added to the medium of the seeded cells. 3 days after transfection, genomic DNA was extracted for PCR assays.
Nested PCR was performed by with a first 30 rounds of PCR across the 3′ end of the expected transgene-rDNA junction, followed by 20 additional rounds of PCR amplification using an inner primer set. One of three replicates of nested PCR performed on genomic DNA extracted from cells treated with the wild-type transposase reaction produced a PCR product of the expected size (approximately 596 bp). In contrast, no PCR product was observed in genomic DNA extracted from cells treated with the frameshift-inactivated R2Tg mutant control, or no-transfection control. The PCR product was gel-purified via Zero Blunt® TOPO® PCR Cloning Kit, and the resulting colonies were Sanger sequenced. Each individual PCR product sequence was then aligned to the expected integration sequence. The fraction of PCR product sequences that align to the expected integrated heterologous object sequence is shown in
This example describes targeted integration of the R2Tg retrotransposon element to mammalian cells via DNA delivery.
Plasmid harboring R2Tg (PLV014) and control plasmid were designed and synthesized as described above in Example 6. Each plasmid was introduced into HEK393T cells via FuGENE® HD transfection reagent. HEK293T cells were seeded in 96-well plate, 10,000 cells/well 24 hr before transfection. On the transfection day, 0.5 μl transfection reagent and 80 ng DNA was mixed in 10 μl Opti-MEM and incubated for 15 min at room temperature. Then the transfection mixture was added to the medium of the seeded cells. 3 days after transfection, genomic DNA was extracted for retrotransposition assays or cells were frozen and underwent targeted locus amplification.
Target locus amplification was performed against hg38 reference human genome and the rDNA locus sequence hsul3369 (GENBANK™: U13369.1). Two independent primer sets were used to perform targeted locus amplification. Analysis with both primer sets showed that the 28S rDNA locus sequence is the only integration site detected above a 1% threshold. Thus, integration of the R2Tg transposon in mammalian cells is specific to this target site.
RNA templates are designed as in previous examples. Two RNAs consisting of a driver and a transgene payload are delivered to mammalian cells. To better promote folding, denaturing the payload RNA by heating to 95 C and cooling to room temperature are performed to encourage proper secondary structure formation. In some embodiments, cooling the RNA to room temperate will increase integration efficiency.
The molar ratio of transgene to driver is also varied to evaluate suitable stoichiometry of components. Integration is analyzed via ddPCR and sequencing. In some embodiments, a higher ratio of driver to transgene is used. In some embodiments, a higher ratio of transgene to driver is used.
Previous examples with cis transgene integration are similarly assayed for stoichiometry of driver to payload. Integration is analyzed via ddPCR and sequencing. In some embodiments, a higher ratio of driver transcription or translation to transgene transcription will result in higher integration efficiency. In some embodiments, a higher ratio of transgene transcription to driver transcription and translation will result in higher integration efficiency.
A hybrid capture experiment was performed to obtain an unbiased view of the specificity of retrotransposon integration into a target site. Retrotransposon experiments were performed as in previous examples by integrating R2Tg flanked by its native UTRs and 100 bp of homology to either side of the expected R2 rDNA target. The rDNA target site had two flanking sets of 100 nucleotides identity to the corresponding native target site. The retrotransposon was delivered to human 293T cells via plasmid or mRNA. Genomic DNA was extracted after 72 hours. After extraction, each genomic DNA sample was subjected to hybrid capture according to protocol with a custom probe set (Twist). Biotinylated probes were designed such that ˜120 bp probes spanned both strands of the R2Tg coding sequence and UTRs. First, a next-generation library was created by fragmentation of the genomic DNA and ligation of sequencing adapters according to a protocol from Twist (available on the world wide web at: twistbioscience.com/ngs_protocol_custompanel_hybridcap). Next, probes were hybridized to genomic DNA libraries and the enriched samples were amplified. Final libraries were seqenced on the MISEQ™ using 300 bp paired-end reads. Custom MATLAB™ scripts were used to analyze reads. The resulting analysis is shown in
Long-range PCR amplification can be performed to measure integration of the desired full-length sequence into the target site in the human genome and to measure whether mutations are introduced during insertion. Retrotransposon integration experiments are performed as described in previous examples. In one example, PCR amplification is used to generate amplicons by designing one primer targeting the genomic integration site and one primer targeting the integrant sequence. In this example, these primers are designed to maximize the length of the amplified genomic locus fused with the integrant sequence. By pooling amplicons spanning both ends of the integrant and performing long-read next-generation sequencing, the fidelity of each integration is be evaluated.
In another example, hybrid capture is performed as described in a previous example but with a larger target library length during initial library generation. The resulting library is then subjected to long-read next-generation sequencing.
In some embodiments, long-read next generation sequencing will show that there are less than 10%, 5%, 2%, 1%, 0.5%, 0.2%, or 0.1% SNPs in the integrated DNA across samples. In some embodiments, long-read next generation sequencing will show that less than 10%, 5%, 2%, or 1% of integrated DNA has a SNP. In some embodiments, long-read next generation sequencing will show that less than 10%, 5%, 2%, or 1% of integrated DNA has an internal deletion. In some embodiments, long-read next generation sequencing will show that less than 10%, 5%, 2%, 1%, 0.5%, 0.2%, or 0.1% of total integrated DNA across the population is deleted. In some embodiments, long-read next generation sequencing will show that less than 10%, 5%, 2%, or 1% of integrated DNA is truncated.
In this example, experiments are designed to characterize suitable lengths and starting positions of homology to the target site for efficient retrotransposon integration. Also, the homology is used to support the mechanism of integration being reverse transcription-driven.
A series of SNPs were introduced within the 100 bp downstream homology of R2Tg plasmids by modifying plasmid PLV014. The design of the SNPs is listed in
This example also describes the evaluation different homology regions to the target site to identify shorter regions that promote efficient integration into the genome. This example describes two approaches. First, different windows of 100 bp of homology to the target site are tested, starting from bp 1-100 3′ of the target site, then testing 2-101 3′ of the target site, 3-103 3′ of the target site, and so on, through bp 30-131 3′ of the target site. Second, shorter lengths of homology to the target site sufficient for DNA integration are tested, starting with bp 0-100 3′ of the target site, then testing 0-95 3′ of the target site, 0-90 3′ of the target site, etc. through bp 0-10 3′ of the target site. After the transfection of each plasmid into 293T cells, ddPCR is used to measure the retrotransposition efficiency.
In this example, different UTR regions with different lengths are evaluated to identify shorter sequences for efficient integration into the genome. The 3′UTR is tested by dividing this 325 bp sequence into 3 regions, 1-100 bp, 101-200 bp, and 201-325 bp. Constructs of R2Tg containing each truncated 3′UTR are generated to test the integration efficiency respectively.
This example describes an evaluation of the effect of exogenous R2Tg retrotranspositon on gene expression, especially tumor suppressor and DNA repair genes. An R2Tg expressing plasmid is delivered to multiple cancer cell lines, including 293T, MCF-7, and T47D. After confirmation of integration in each cell line, RNA-seq is conducted to assess the effect on gene expression profile. Gene set enrichment analysis is then applied to evaluate whether any DNA repair pathways are upregulated after retrotransposition. MCF-7 and T47D are breast cancer cell lines with wild type and mutant p53 respectively, which are be used to evaluate the relationship between p53 and retrotranspositon specifically. In some embodiments, p53 is not upregulated when a retrotransposon GENE WRITER™ integrates into the genome. In some embodiments, no DNA repair genes are upregulated when a retrotransposon GENE WRITER™ integrates into the genome. In some embodiments, no tumor suppressor genes are upregulated when a retrotransposon GENE WRITER™ integrates into the genome.
In this example, experiments will test the effect of different DNA repair pathways on R2Tg retrotransposition via the application of DNA repair pathway inhibitors or DNA repair pathway deficient cell lines. When applying DNA repair pathway inhibitors, PrestoBlue cell viability assay is performed first to determine the toxicity of the inhibitors and whether any normalization should be applied for following assays. SCR7 is an inhibitor for NHEJ, which is applied at a series of dilutions during R2Tg delivery. PARP protein is a nuclear enzyme that binds as homodimers to both single- and double-strand breaks. Thus, its inhibitors are be used in the test of relevant DNA repair pathways, including homologous recombination repair pathway and base excision repair pathway. The experiment procedure is the same with that of SCR7. Cell lines with deficient core proteins of nucleotide excision repair (NER) pathway are used to test the effect of NER on R2Tg retrotransposition. After the delivery of R2Tg element into the cell, ddPCR is be used to evaluate the retrotransposition in the context of inhibition of DNA repair pathways. Sequencing analysis is also be performed to evaluate whether certain DNA repair pathway plays a role in the alteration of integration junction. In some embodiments, R2Tg integration into the genome will not be decreased by the knockdown of any DNA repair pathways, suggesting that R2Tg does not rely on the host cell pathways for DNA integration.
In this example, the previously performed R2Tg retrotransposition analysis of 293T cells is repeated in non-dividing cells, including fibroblast and T cells. Compared to 293T cells, non-dividing cells are sometimes more difficult to transfect with lipid reagent. Thus, nucleofection is used for the delivery of R2Tg element. The subsequent retrotransposition assay for integrating efficiency and sequencing analysis will be performed as described herein for 293T cells. In some embodiments, R2Tg integrates into the genome of fibroblasts and T cells.
In this example, a quantitative assay is used to determine the frequency of targeted genome integration at single cell level, and that information can be compared to the copy number of targeted genome integration per genome quantified from genomic DNA.
Approximately 5000 transfected cells will be collected and mixed with ddPCR reaction mixture before distributing into about 20,000 droplets, with the aim of each droplet containing one cell or no cells. ddPCR assays including 5′UTR and 3′UTR assays will be performed as described above to determine the frequency of R2 or transgene integration at single cell level. A control experiment will be performed in parallel using genomic DNA harvested from the same number of cells to determine the targeted genome integration efficiency per genome. In some embodiments, the frequency of targeted genome integration at the single cell level is calculated to be 1-80%, e.g., 25%, wherein the indicated percentage of cells have one or more copies of the transgene integrated into the desired locus.
In this example, a quantitative assay is used to determine genome integration copy number in cell colonies derived from single cell.
Single cell colonies will be isolated by colony picking up or by limited dilution and cultured in a 96 well format. When the cells reach >80% confluency, half of the cells will be frozen for backup and genomic DNA from the other half of the cells will be harvested for ddPCR. Optimized ddPCR assays including 5′UTR and 3′UTR assays will be performed as described previously to determine the frequency of R2 or transgene integration. At least 96 colonies will be screened for each R2 element with appropriate controls. The total number of colonies to be screened will be determined by single cell ddPCR data if applicable or the first set of single cell colony screen data. In some embodiments, the frequency of targeted genome integration at the single cell level will be calculated to be 1-80%, e.g., 25%, wherein the indicated percentage of cells have a single copy of the transgene integrated into the desired locus. The assay can also be used to determine the percentage of colonies that have more than one copy of the transgene integrated into the desired locus.
The DNA targeting module of wild-type R2 is made of a cysteine-histidine zinc finger and c-Myb transcription factor binding motifs. This N-terminal module can be substituted with different DNA binding modules such as DNA binding protein(s) (e.g., transcription factors), zinc finger(s) (e.g., natural or designed motifs), and/or nucleic acid guided, catalytically inactive endonucleases (e.g., Cas9 bound with a guide RNA (e.g., sgRNA) to form a Cas9-RNP). This DNA binding module is swapped for the naturally occurring module and, in some cases placed with a flexible linker attaching it to the RNA binding/RT module. Additionally, in some constructions, this new DNA binding module is placed in tandem with the same and/or different DNA binding modules. Furthermore, some constructions may split the GENE WRITER™ protein where one protein molecule contains the RNA binding module and the other protein contains the RT and endonuclease modules. In some embodiments, swapping of the DNA module increases specificity and/or affinity to a genomic location and in some cases allows for the specific targeting of new genomic locations.
DNA binding activity of GENE WRITER™ genome editor polypeptides described herein (and DNA binding domains for the same) can be tested, e.g., as described in this example. DNA binding modules are purified by recombinantly expressing them in cells (e.g., E. coli) or they are expressed in a cell-free reactions of transcription and translation (e.g., T7 RNA polymerase+wheat germ extract). The purified DNA binding module(s) is tested for binding affinity by measuring the Kd in a binding assay (e.g., EMSA, Fluorescence anisotropy, dual-filter binding, FRET, SPR, or thermophoresis (temperature related intensity change). The protein (DNA binding module) is labeled and/or the DNA molecule is labeled with a molecule that is compatible with the above binding assays (e.g., dye, radioisotope (for example, Protein: 35S-methionine, maleimide dye, DNA: 32P end or internal label, DNA with a linked amine reacted with NHS-ester dye). The molecules are measured by changing their concentrations and fitting to a binding curve which calculates the binding affinity. In some assays, the nucleic acid sequence specificity is tested by mutational analysis of the DNA sequence or mutation to the DNA binding module by amino acid changes or alterations to protein-nucleic acid complex (e.g., Cas9-RNP DNA binding module). In some embodiments, increasing the Kd of the DNA binding module will decrease off-target insertions and, in some cases, will increase the activity of on-target sites by increasing the dwell time of the R2-RNA complex at the specific genomic location.
The DNA binding module is expressed in cells (e.g., animal cells, e.g., human cells) as the DNA binding module alone, in the context of the full-length retrotransposon R2, or a control without retrotransposase. The expression of the module or retrotransposon is delivered to cells using conventional methods of delivering DNA, RNA, or protein. The complex is crosslinked (e.g., using chemical or UV light) or is not crosslinked. The cells are lysed and treated with DNase I so that only the bound DNA is protected from degradation. DNA is extracted, NGS library preparation of DNA fragments and de novo binding sites are identified, analogous to ChIP-seq or DIG-seq. In some embodiments, potential off-target sites are identified that can be followed-up to remove false-positives. In other embodiments this assay confirms the in vitro assay on the specificity of the DNA binding module to bind at its intended site and not at others.
An orthogonal assay to identify DNA binding sites in high-througput uses the method described by Boyle et al, PNAS 2017 where the DNA binding domain is tested in a cell-free setting to determine specificity along with systematic analysis of sequence mutants related to the new DNA binding module.
The RNA molecule binds to the R2 protein via interactions found in the reverse transcriptase module, designated as a sub-module “RNA binding”. The protein recognizes specific structures in the 5′ and/or 3′ UTRs to interact with the RNA. In some embodiments, swapping of the UTR modules increases protein interactions, changes the protein specificity to bind the UTR, stabilizes against nucleases, and/or improves cellular tolerance (e.g., leads to a reduced innate immune response). In other embodiments, addition and/or swapping of the RNA binding module of the R2 protein is compatible with the use of different sequence or ligands that are linked to the transgene and/or element module of the RNA. In some embodiments, combinations of new ligands in place of the UTRs will have better affinity to the RNA binding domain of R2 and lead to better insertion efficiency. In some embodiments, the changes to the sequence of the UTRs or changes to the base modifications of the UTRs will increase the secondary structure stability that leads to better interaction with the RNA binding module.
New UTR modules are tested in a binding assay. In the case of new RNAs, they are synthesized either by cell-free in vitro transcription using a synthetic DNA template or by chemical synthesis of the RNA in full-length or chemical synthesis of pieces that are ligated together to form a single RNA molecule. The binding affinity of the purified UTRs are measured in a binding assay (e.g., EMSA, Fluorescence anisotropy, dual-filter binding, FRET, SPR, or thermophoresis (temperature related intensity change)). The UTR module and/or RNA binding module/RT module is detected with or without a label which is described above for labeling RNAs. Measurement of the molecules at different concentrations is performed to determine a binding affinity. In some embodiments, alterations to/swapping of the 5′ and/or 3′ UTR binding module and/or changes to the RNA binding/RT module will lead to better interactions than the wild-type R2 protein or UTR. In some embodiments, the increased interaction will lead to an increase in the efficiency of retro-transposition and in some cases increases specificity of the R2 protein to interact with the RNA.
While not wishing to be bound by theory, in some embodiments the UTRs act as a handle for the R2 protein to interact with the RNA which it uses as a template for RT in concert with it binding a genomic location, nicking the DNA with its endonuclease module, and then using the bound RNA as a template for RT insertion at the cleavage site in the DNA. For the UTR to keep the template in close proximity to the RT module, then the UTR modules can be substituted with different ligands that would bind to a specific RNA binding module engineered into the R2 protein. Thus, in some embodimetns, the alternative non-RNA UTR is either a protein, small molecule, or other chemical entity that is attached covalently, through protein-protein interaction, small molecule-protein interaction, or through hybridization. In some embodiments the RNA binding module binds specifically to a ligand that is not RNA that is attached to the transgene module RNA that increases the efficiency, stability, and/or rate of retro-transposition.
Binding assays to measure affinity of R2 protein with engineered UTRs are performed as described above, e.g., for a protein-nucleic acid interaction. In cases of protein-protein or protein-small molecule interactions the assay uses a label on the RNA transgene module where the UTR module is attached.
In this example, GENE WRITING™ technology is delivered to target cells and to non-target cells, and new DNA is integrated into the genome in target cells at a higher frequency than in non-target cells. As described in more detail below, this approach takes advantage of the non-target cell having an endogenous miRNA that the target cell does not have (or has at a lower level). The endogenous miRNA is used to reduce DNA integration in the non-target cell.
The polypeptide used is the R2Tg protein and the template RNA component is RNA coding for the GFP protein and flanked at the 5′ end by the 5′ UTR and at the 3′ end by the 3′ UTR of the R2Tg retrotransposase. The 5′ UTR is flanked by 100 bp of homology to the 5′ of R2Tg 28s rDNA target site and the 3′ UTR is flanked by 100 bp of homology to the 3′ of R2Tg 28s rDNA target site. The GFP gene is facing in the antisense direction with regard to the 5′ and 3′ UTRs and has its own promoter and polyadenylation signal.
The template RNA further comprises a microRNA recognition sequence. This microRNA recognition sequence is bound by microRNAs in the non-target cells, leading to the inhibition (e.g., degradation) of the template RNA prior to genomic integration.
In this example the target cells are hepatocytes and the non-target cells are macrophages from the hematopoietic lineage. The target cells and non-target cells are cultured separately. The template RNA and retrotransposase protein can be delivered to cells as described herein, e.g., as RNA or using viral vectors (e.g. adeno-associated viral vectors), wherein the template RNA is transcribed from viral vector DNA.
Three days after treating the cells, GFP expression and genomic integration are assayed.
GFP expression is assayed via flow cytometry. In some embodiments, GFP expression will be higher in the hepatocyte population than in the macrophage population.
Genomic integration (in terms of copy number per cell normalized to a reference gene) is assayed via droplet digital PCR using methods described herein. In some embodiments, genomic integration will be higher in the hepatocyte population than in the macrophage population.
In this example, a series of experiments were performed to test the activity of various mutant retrotransposases, as well as gaining structural knowledge about these proteins. This experiments tested flexible linkers in different locations and lengths, in order to determine if the DNA binding domain (DBD) was modular. These experiments also provide support for being able to separate the DBD from the rest of R2Tg and replacing it with any DNA targeting protein sequence. This example thus supports an understanding that the transposases described herein can withstand the tested levels of sequence divergence at a plurality of locations (e.g., in the predicted −1 RNA binding motif, in an alpha helix, and in a coil region located C-terminal to the predicted c-myb DNA binding motif, e.g., as described below) identified by structural modeling, while maintaining function.
Briefly, the two linkers (Linker A: SGSETPGTSESATPES (SEQ ID NO: 1023), and Linker B: GGGS (SEQ ID NO: 1024)) were inserted into 3 locations, noted herein as versions v1, v2, and v3. vi was located at the N-terminal side of an alpha helical region of R2Tg that preceded the predicted −1 RNA binding motif, v2 was located at the C-terminal side of an alpha helical region of R2Tg that preceded the predicted −1 RNA binding motif, and v3 was located C-terminal to a random coil region that came after the predicted c-myb DNA binding motif of R2Tg. For each of v1, v2, and v3, one of linkers A or B were added by PCR to a DNA plasmid that expressed R2Tg, thereby yielding sequences v1A (v1+linker A), v1B (v1+linker B), v1C (v1+linker C), v2A (v2+linker A), v2B (v2+linker B), and v2C (v2+linker C), as shown in Table 5 below. The insertion of the linkers was verified by Sanger sequencing and the DNA plasmids were purified for transfection.
HEK293T cells were plated in 96-well plates and grown overnight at 37° C., 5% CO2. The HEK293T cells were transfected with plasmids that expressed R2Tg (wild-type), R2 endonuclease mutant, and linker mutants. The transfection was carried out using the Fugene HID transfection reagent according to the manufacturer recommendations, where each well received 80 ng of plasmid DNA and 0.5 μL of transfection reagent. All transfections were performed in duplicate and the cells were incubated for 72 h prior to genomic DNA extraction.
Activity of the mutants was measured by a ddPCR assay that quantified the copy number of R2Tg integration per genome. The 5′ and 3′ junctions were quantified by generating two different amplicons at each end.
v3 (near the c-myb binding motif in the DBD) decreased integration activity with either linker A or B. v1 (N-terminal to the alpha helix preceding the −1 RNA binding motif) had comparable activity to the wild-type when used with linker A (16 AA) versus the shorter linker B (4 AA). This could be related to amino acid selection, length, or three-dimensional structure. v2 (C-terminal to the alpha helix preceding the −1 RNA binding motif) did not tolerate linker A; however, linker B had activity that was comparable and slightly better than the wild-type. v1 and v2 may therefore be considered preferred locations to add a linker that can separate R2Tg's DNA binding domain and the rest of the protein.
Retrotransposon integration experiments were performed as described in previous examples. In one example, PCR amplification was used to generate amplicons by designing one primer targeting the genomic integration site and one primer targeting the integrant sequence. In this example, these primers were designed to maximize the length of the amplified genomic locus fused with the integrant sequence. By pooling amplicons spanning both ends of the integrant and performing long-read next-generation sequencing, the fidelity of each integration was evaluated.
A cis construct of R2Tg was integrated into 293T cells via plasmid transfection as described herein. Amplicons spanning each end of the integrations were generated with flanking randomized UMIs to control for PCR bias. These amplicons were sequenced with PacBio next-generation sequencing. The resulting sequences were collapsed to remove reads with identical UMIs. By aligning unique reads, a coverage plot was constructed as shown in
In another example, hybrid capture may be performed as described in a previous example but with a larger target library length during initial library generation. The resulting library can then be subjected to long-read next-generation sequencing.
This example describes targeted integration of the R2Gfo and R4Al retrotransposon elements to mammalian cells via DNA delivery.
In one example, we assayed the full R2 element R2-1_GFo (Repbase; Kojima et al PLoS One 11, e0163496 (2015)) from the medium ground finch, Geospiza fortis (“R2GFo”). In another example, we assayed the full R4 element R4_AL (Repbase; Burke et al Nucleic Acids Res. 23, 4628-34 (1995)) from the large roundworm, Ascaris lumbricoides (“R4Al”). Because non-LTR R2 and R4 elements are not present in the human genome and are thought to be highly site-specific, the ability of retrotransposons to accurately and efficiently integrate itself into the human genome would demonstrate the capability to perform genomic targeted integration.
Plasmids harboring R2Gfo (PLV033) or R4Al (PLV462) were designed for cis integration of the R2Gfo or R4Al elements as in previous examples. Plasmids were synthesized such that the wildtype element was flanked by its native un-translated regions (UTRs) and 100 bp of homology to its rDNA target (
ddPCR was performed to confirm integration and assess integration efficiency. A Tagman probe was designed to the 3′UTR portion of each element. A forward primer was synthesized to bind directly upstream of the probe, and a reverse primer was synthesized to bind the rDNA. Thus, amplification of the expected product across the integration junction would degrade the probe and create a fluorescent signal. The results of the ddPCR copy number analysis (in comparison to reference gene RPP30) are shown in
This example describes the cis integration of R2Tg into human fibroblasts. Briefly, a plasmid designed to integrate R2Tg in cis was synthesized such that R2Tg was flanked by its native UTRs and homologous sequence to its rDNA target as in previous examples. 0.5 μg PLV014 (wild-type) and PLV072 (EN mutant) plasmids were transfected into 100,000 human dermal fibroblasts isolated from neonatal foreskin (HDFn, C0045C, ThermoFisher Scientific) respectively using the Neon transfection system. Two programs were performed, each in duplicate. The setting for Program 1 was 1700V pulse voltage, 20 ms pulse width, and 1 pulse number. The setting for Program 2 was 1400V pulse voltage, 20 ms pulse width, and 2 pulse number. Both programs achieved 95% transfection efficiency measured using plasmid encoding the EGFP. Three days post transfection, genomic DNA was extracted for the ddPCR assay. ddPCR was performed to confirm integration and assess integration efficiency. A Tagman probe was designed to the 3′ UTR portion of the R2Tg element. A forward primer was synthesized to bind directly upstream of the probe, and a reverse primer was synthesized to bind the rDNA. Thus, amplification of the expected product across the integration junction would degrade the probe and create a fluorescent signal. The results of ddPCR copy number analysis (in comparison to reference gene RPP30) are shown in
DNA damage (e.g., resulting from DSB formation or replication fork collapse) leads to the activation of p53, which among many other transcriptional responses, leads to the upregulation of p21, resulting in cell cycle arrest or apoptosis. Genome editing using CRISRP/Cas9 has been shown to activate p53 and p21, which is a potential safety and efficacy problem for CRISPR/based therapeutics. To establish whether R2Tg delivery to the cell leads to activation of p53 and p21, U2OS cells were seeded at a density of 4×104 cells/well and transfected 24 hours later using the Fugene HD and Lipofectamine reagents with either 500 ng of R2Tg-WT plasmid or 500 ng of R2Tg-EN (a variant of R2Tg with a mutation in the endonuclease (EN) domain, rendering R2Tg inactive). To control for transfection efficiency, U2OS cells were also transfected with a plasmid expressing GFP. Lastly, as a positive control for p53 and p21 activation, U2OS cells were treated with one of the DNA damage-inducing agents etoposide (20 μM) or bleomycin (10 μg/ml). The U2OS cells were collected 24 hours after transfection/treatment. Protein lysates were prepared in RIPA buffer and run on an SDS-PAGE gel, followed by transfer to nitrocellulose, followed by probing with antibodies against p53 and p21, as well as Actin and Vinculin. As shown in
This application is a Divisional of U.S. application Ser. No. 16/706,448, filed Dec. 6, 2019, which is a Continuation of International Application No. PCT/US2019/048607, filed Aug. 28, 2019, which claims priority to U.S. Ser. No. 62/723,886 filed Aug. 28, 2018, U.S. Ser. No. 62/725,778 filed Aug. 31, 2018, U.S. Ser. No. 62/850,883 filed May 21, 2019, and U.S. Ser. No. 62/864,924 filed Jun. 21, 2019, the entire contents of each of which is incorporated herein by reference.
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62864924 | Jun 2019 | US | |
62850883 | May 2019 | US | |
62725778 | Aug 2018 | US | |
62723886 | Aug 2018 | US |
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Parent | 16706448 | Dec 2019 | US |
Child | 18623612 | US |
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Parent | PCT/US2019/048607 | Aug 2019 | WO |
Child | 16706448 | US |